Imágenes de páginas
PDF
EPUB
[ocr errors][ocr errors]

black and white and the amount and distribution of these colors are variable to the same extent in specimens from the eastern and western Atlantic.

3. The measurements of external proportions of the body and fins show a substantial agreement, except as regards the spread of the flukes, in which there is an unexplained variability.

4. The abdominal folds agree in number, size, and especially in arrangement.

5. The dermal tubercles on the head agree well in number, size, and general arrangement, though there is a large individual variation.

6. There is no constant difference in the shape of the dorsal fin between the American and European Humpbacks, unless it be that the tip is thicker in Greenland specimens.

7. The pectoral fin agrees in length, breadth, and especially in the protuber . ances of the margins.

8. The flukes are alike in form, with a possible difference in spread.

9. The outline of the caudal peduncle or “small” is alike in Newfoundland and Norwegian specimens.

10. The skeleton agrees closely in the number of vertebra and the formula for the same; in the proportions of the skull and of the bones of the limbs. The Greenland Humpback, however, appears from Eschricht's figure to have smaller nasals than the others, and more deeply emarginated frontal orbital processes, but there is a strong presumption that the figure is inaccurate.

Considering the difficulties encountered in instituting exact comparisons between data recorded at different times by different observers, the agreement is sufficiently close to justify the opinion that the Humpback whales of the North Atlantic are all referable to the same species. In other words, the differences between the noinival species M1. nodosa, longimana, osphyia, bellicosa, americana, etc., are not substantiated.

Although the type-skeleton of M. osphyia Cope, which in the foregoing pages has been currently treated as representing the common Humpback of the western North Atlantic, shows no differences which would render such treatment unwarranted, it seems to me desirable to consider a little further the differences by which Cope supposed it could be separated from M. longimana.

Cope compares his species with M. longimana as described in the works of Rudolphi, Gray, and Flower, and concludes that it is different for the following

[ocr errors][ocr errors][ocr errors][merged small]

reasons:

[ocr errors]

1. M. osphyia has long inferior lateral processes in the posterior cervical vertebræ.

2. The atlas is a parallelopiped in form, the transverse processes are elevated, and there is an “internal process.”

3. The cranium is broader in proportion to its length than in M. longimana, and shorter in proportion to the total length of the skeleton.

4. The pectoral fins are shorter.
5. The vertebræ and chevrons are less in number.
6. The first pair of ribs is very broad.
7. The spines of the lumbar vertebræ are much higher.

It

I have already shown that the 4th and 7th characters are fictitious, as advanced by Cope, and that the 1st is merely an individual variation.

The width of the cranium of the type of M. osphyia (3d character) as compared with the length, differs from that in the Scotch skulls carefully measured by Struthers by only 1.1 per cent., which in actual measurement amounts to only 1} inches. This is certainly not significant, and is within the limit of variation of different American specimens of the Humpback among themselves.

The number of vertebræ (5th character) in the type-skeleton as mounted is 48, probably to be distributed as follows: C. 7, D. 14, L. 10, Ca. 17 (+) = (48 +). The last vertebra present is 4 in, square, and according to Struthers's measurements of M. longimana, about 4 more caudals must have been present originally, making 52 for the whole column, which is the average for M. longimana. Of chevrons there are 7 in position in the type of M.osphyia, with places for perhaps 10 in all. Van Beneden and Gervais give 12 as the number for M. longimana, but it is to be remarked that Struthers's Tay River (Scotland) specimen bad but 10 chevrons, and the skeleton in the National Museum (No. 16252) from Cape Cod, Mass., but 9, so that it would appear that the number is variable, and unreliable as a specific character.

In the type of M. osphyia the breadth of the first rib on the left side is 9 in., and on the right 74 in. In Struthers's Tay River specimen the right rib of the first pair has a maximum breadth of 8.6 in., and the left, 5.3 in. It is obvious that the breadth is so variable even on the two sides of the same skeleton that it is useless as a specific character, but in this instance, as the skull of Struthers's specimen is but 125 in. long, while that of M. osphyia is 135 in. long, the maximum breadth of the first ribs in the two skeletons is practically the same relatively, with a little increase in favor of the European specimens.

In 1868 Cope cited as an additional character of M. osphyia the contraction of the orbital process of the frontal at the distal extremity (27, 194). He remarks: “ The orbital processes of the frontal bone are not contracted at the extremities as in M. longimana, but are more as in Balanopteræ ; entire width over and within edge of orbit, 15} in.” This measurement I make 14 in. instead of 154 in. The former equals 10.4 % of the length of the skull. As shown in the table on p. 233, the same measurement from Rudolphi's figure of the type of M. longimana is 9.0 %, and of Struthers's Tay River specimen 9.6 %, while the type of M. bellicosa gives 10.7%. This approximation shows that M. osphyia presents no great deviation in the breadth of the supraorbital edge of the frontal. It is true that in Rudolphi's figure of the whole skeleton of the type of M. longimana the orbit itself appears smaller, but in a general figure of this kind the proportions of the smaller parts are frequently inaccurate. The least longitudinal diameter of the orbit in Struthers's Tay River whale is, according to his measurements, the same as in the types of M. osphyia and M. bellicosa. As it is extremely unlikely that the two European skele. tons belong to different species, the probability that Rudolphi’s figure is inaccurate as regards the orbit is strengthened by this circumstance.

The Humpback appears to have been known to European zoologists only from

[ocr errors][ocr errors][ocr errors][ocr errors][merged small]

American sources, until the time of Rudolphi's description of M. longimana in 1832. This author suspected that his species might be the same as Fabricius's boöps, and Schlegel in 1844 was of the same opinion.

In 1848 Eschricht arrived at the same conclusion from an opposite point of view, and in 1849 stated emphatically: “It is now raised beyond all doubt that the whale stranded in the mouth of the Elbe River in 1824, and described by Rudolphi as Balæna longimana, is nothing more and nothing less than an individual of the commonest species of baleen whale on the Greenland coast, known to the Greenlanders as the Keporkak; also mentioned by Anderson under the latter name and introduced into systematic zoology by Klein and Bonnaterre under the appropriate name Balæna nodosa(37, 57). As this latter name is derived from the description of the New England Humpback, Eschricht combines not only the Greenland and European Humpbacks but those of the coast of the United States as well, in one species. Gray, however, was not content to have it so, and already, in 1846, separated the “Bermuda Humpback” under the name of Megaptera americana (56). In 1866 he still adhered to this arrangement, employing the name M. americana as before and citing Fabricius's Balena boöps with a mark of interrogation, under M. longimana, with the comment: “Rudolphi, and after him Schlegel, refer B. boöps, 0. Fabricius, to this species; and Professor Eschricht has no doubt that Baluna boöps of O. Fabricius is intended for this species, as it is called Keporkak by the Greenlanders. If this be the case, Fabricius's description of the form and position of the dorsal fin and the position of the sexual organs is not correct” (53, 124), Gray seems not to have known at this time of Cope's description of M. osphyia, published in 1865. In the supplement to his catalogue he quotes Cope's description, but without comment.

In 1869, Van Beneden and Gervais remark as regards osphyia and boöps (= longimana): “We do not find any difference of value for separating them" (8, 236). and again in 1889 Van Beneden unites all the American Humpbacks in one species.

Fischer (44, 58), who studied the Humphack bones from Martinique Id. in the Bordeaux museum, which should presumably represent M. bellicosa, was unable to decide whether they should be assigned to the same species as the Greenland Humpback, and closes his investigation with the inquiry whether all the Humpbacks should not be regarded as belonging to a single species.

[ocr errors][ocr errors][ocr errors]

NOTE.—Two excellent illustrations of the Newfoundland Humpback, from negatives obtained by Mr. Wm. Palmer, of the U. S. National Museum, in 1903, are reproduced on plate 38, figs. 1 and 2. The individual represented in fig. 1 is unusually white and on that account especially interesting.

[merged small][ocr errors]

CHAPTER VIII.

THE NORTH ATLANTIC RIGHT WHALE, BALÆNA GLACIALIS BONNATERRE.

Since the separation of the Right whale of the temperate eastern Atlantic from the Arctic Right whale by Eschricht, the validity of the former species has been universally accepted, though opinions have differed as to whether its American counterpart is identical with it. The European species, known as the Nordcaper or Sarde, was named Balona glacialis by Bonnaterre (9, 3) and Balana biscayensis by Eschricht (1860). The latter name was not accompanied by a description. Bonnaterre’s diagnosis does not include a reference to a type-specimen. Unless there is more than one species on the European coasts, we may, therefore, draw characters from whatever specimens have been described. As would naturally be expected, the later accounts are generally fuller and more accurate than the earlier ones, but even the fullest descriptions are to a certain extent fragmentary and unsystematic and contain contradictory statements and measurements. Το thread one's way through the maze requires a large amount of patience and con. sumes a great deal of time, and the results obtained are not entirely satisfactory.

My study of the literature of the European Right whale, and of American specimens, leads me to believe that there is a greater amount of individual variation as regards proportions in the genus Balana than in Balænoptera, and that we may not look for the same conformity in this respect in the former as in the latter. It is possible, of course, that there may be several species of Balona on the European coasts and an equal number on the Atlantic coasts of North America, but there appears to be no real foundation for such an opinion. To a certain extent the variations in proportions observable among specimens hitherto described are, no doubt, due to differences in age and to inaccurate measurements. It will be found that in general appearance, color, form of parts, etc., the European specimens agree well together.

The European specimens which have been described are few indeed. The most celebrated is that captured at San Sebastian, Spain, in 1854. It was a young individual 24 ft. 9} in. long. It enabled Eschricht to prove his assumption that the Right whale of the temperate eastern Atlantic was a different species from the Arctic Right whale. He intended to publish a detailed account of it, but died before the work was accomplished (Fischer, 44, 19). Dr. Monedero in San Sebastian published a lithographic figure of this specimen, with measurements which have been copied by Fischer (44, 19), Gasco (48, 587), etc. This figure has been highly

244

praised, and often copied, but it hardly seems possible that the remarkably short head can be correct. The skeleton was very fully described by Gasco in 1879 (48).

Fischer, in 1881, reprinted the description and measurements (44, 10) published in 1682 by Segnette of a specimen stranded on Ré Id., France, in 1680.

In 1877, a specimen was stranded at Taranto, Italy, of which descriptions and figures were published by Capellini in 1877 (13) and by Gasco in 1878 (47). It is an unfortunate circumstance that Gasco's measurements do not agree with Capel. lini's; nor do they agree with the figures in the plates accompanying his memoir, nor do the figures agree with each other.

In 1889 Graells (52) published measurements and figures of a specimen captured at Guetaria, Spain, in 1878, and preserved in the museum of the Institute of Secondary Instruction at San Sebastian. In the same memoir are included additional facts regarding this specimen by Prof. Candido Rios y Rial (52, 63-67, sep.).

In 1893, Prof. Guldberg published a very valuable article entitled Zur Kennt niss des Nordkapers (59), containing measurements of specimens taken at Iceland, together with three photographic figures of the exterior, and figures of the pelvic bones and sternum.'

The foregoing memoirs contain practically all the data on the Nordcaper avail. able for use in comparing European with American specimens.

[ocr errors][ocr errors][ocr errors]

SIZE.

The total length of the various recorded specimens of the European Nordcaper is as follows:

[ocr errors]

BALÆNA GLACIALIS BONNATERRE. EUROPEAN. TOTAL LENGTH.

[ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][merged small][ocr errors]

1

2

[ocr errors]

'These figures on a larger scale were also published by Buchet in 1895 in Mem. Soc. Zool., France, 8, 1895, 229-231, pls. 6–8. They bear here the legend“ Phot. de M. Berg"-In Guldberg's paper the legend is “Guldberg phot.”

Skeleton. Van Beneden cites this as 48 ft. long, which must be an error.
F.= French measure; R.= Rheinland; S.= Spanish. I am not positive as to the Rheinland.
In a straight line.
Fischer states that this specimen was young, but there is no evidence that such was the case.

3

4

5

« AnteriorContinuar »