Imágenes de páginas
PDF
EPUB

found in the case of both B. physalus and Megaptera, the latter hypothesis appears more probable.

2. In external proportions, so far as may be judged from the limited data available in the case of European specimens, there is a very close correspondence between the Sulphurbottoms of the Eastern and Western North Atlantic, amounting to identity.

3. In coloration no important difference is exhibited.

4. The whalebone is of the same color in both American and European specimens and, so far as may be judged, of equal length.

5. The lack of records and material precludes a judgment as to osteological characters, though in such matters as the total number of vertebræ and ribs, general shape and size of the individual bones of the skull, shape of the scapula, etc., there is no clear indication of specific differences. Cope's suspicions that the Ocean City, New Jersey, specimen represented a species intermediate between B. physalus and B. musculus are not confirmed.

Viewing the present evidence as a whole there appears to be no reason for separating the American Sulphurbottom from B. musculus (L.).

THE REPRESENTATIVE OF B. MUSCULUS (L.) IN GREENLAND WATERS.

As mentioned on a previous page, Robert Brown and others assert that the Greenlanders recognize two or more species of large Finbacks under the name of Tunnolik. Fabricius (41, 35) identified the Tunnolik with B. physalus (L.) and gave a diagnosis and a few data regarding its habits and utilization. These standing by themselves are insufficient for the determination of the species and of no value in a case where the discrimination of closely allied forms is involved.

Scoresby (84, 1, p. 481) mentions a "Physalis found dead in Davis' Strait," which was 105 ft. long. Although the length is exaggerated, this specimen is prob ably to be assigned to B. musculus, as he states that the color was "bluish-black on the back and bluish-gray on the belly." The data he gives are insufficient for a positive identification.

In 1846 Eschricht (36, 373) published a description and measurements of a female Tunnolik stranded at Godhavn, August 12, 1843, which account he obtained from H. P. C. Möller who examined the specimen. Möller's description contains the following data:

Body more elongate than in Balana mysticetus, Megaptera longimana, or Balaenoptera acuto-rostrata.

Fore part of body thick and heavy; hind part slender and thin, much compressed.

Color black throughout, or possibly lighter under the posterior part of the body; within folds of the skin, e.g., about mamma, or genitals, dark mouse-gray. Pectorals white below.

Upper jaw a foot shorter than the lower. Lower jaw with a rounded terminal protuberance and faint median keel.

Baleen very short and proportionately very broad.

Dorsal fin unusually small and thin and situated behind the line of the genital

orifice.

The dorsal fin of this specimen was sent to Eschricht in salt, and is described by him as follows (36, 378):

"The fin itself, extremely small (4 inches high) and flat and narrow, with the point curved backward, stood on a thick tuberous root, which apparently might be regarded as the base of the fin."

Eschricht also received from Möller one of the pectoral fins, of which he gives a description and figure (36, 379). He found that it was quite different in form from the pectorals of the Humpback and Little Piked whale, and that the phalanges were 5, 5, 6, 3. Its length was the total length of the whale.

Möller's measurements of the exterior were as follows:

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

While considering that the identity of this specimen could not be positively determined, Eschricht, with his usual sagacity, reached the conclusion that it was probably the same as the celebrated Ostend specimen. In this he was entirely justified. The Ostend specimen is now known to have been a Sulphurbottom, B. musculus (L.).

Möller's measurements, reduced to percentages of the total length and compared with the average of the ten Newfoundland females of B. musculus, measured by myself, are as follows:

'The pectoral preserved in the Copenhagen Museum measures 11 ft.-ESCHRICHT.

[blocks in formation]

The correspondence between these measurements is sufficient to show that the Greenland specimen is at least very close to the Newfoundland Sulphurbottom, if not identical with it, which probability is strengthened by many points in Möller's description. The chief differences shown here and in the other data given by Möller are: (1) the dorsal fin is lower; (2) the color is black.

Regarding these points it may be said, first, that in view of Eschricht's remarks regarding the dorsal fin, it is uncertain whether Möller measured the height in the same manner as myself; second, Möller's specimen had been dead three days when he saw it and perhaps much longer, so that it is quite natural it should be described as black. It is to be noted that the parts protected from the light are described as gray.

The case of this Greenland specimen (and the species it represents) remains, therefore, substantially as Eschricht left it, namely, with a very strong probability that it was identical with B. musculus (L.), but with positive determination impossible from lack of more extended data.

'This length is from the tip of the mandible to the notch of the flukes. In computing the percentages here and on p. 159, eighteen inches were subtracted for the overhang of the lower jaw. 'To the middle of the genital orifice.

CHAPTER VI.

THE LITTLE PIKED WHALE, BALÆNOPTERA ACUTO-ROSTRATA LACÉPÈDE.

Sars's diagnosis of this species is as follows:

1. Length of full-grown individuals 20 to 30 feet. (Maximum 36 feet-Van Beneden.)

2. Body less slender than in the other species of the genus, the greatest depth equalling the length; behind the navel gradually narrower; tail with a rather high crest above and below.

3. Color above and on the sides of the lower jaw gray-black; below white; dark color of the back descending obliquely behind the pectoral fins and occupying the greater part of the tail.

4. Length of the mouth exceeding the total length; upper jaw seen from above, becoming attenuated rapidly from the base, with the extremity acute, pale gray.

5. Pectoral fins small, scarcely exceeding the total length, lanceolate, forming an obtuse angle posteriorly at about the middle of the length; the middle of the external surface with a broad transverse band of pure white, sharply defined proximally, less so distally; base and tip black.

6. Dorsal fin quite high, with the tip strongly curved backward, like a horn. It lies quite far forward with the anterior insertion at the commencement of the last third of the total length, and in advance of a vertical line drawn through the

anus.

7. Flukes below whitish, with irregular dark markings.
8. Baleen entirely yellowish-white (79, 15).

Plate 1 accompanying Sars's memoir represents a female 14 ft. long, captured near Christiania, Norway, September, 1878. The original drawing was by Sars. It is an admirable figure in every respect, and corresponds exactly with the foregoing diagnosis.

Dr. Collett added the following characters in the diagnosis of the species given by him in 1886: "Number of plates [of baleen] about 325; their greatest length about 200 mm., not including the bristles." "Inner side [of the flippers] quite white" (21, 264). Bocourt's figure of the Bretagne specimen (49, pl. 3), which is in most respects very satisfactory, shows a broader white band on the under surface of the pectoral than on the upper surface, with the margins nearly as well defined. As I am acquainted with but three specimens from the east coast of the United States which may be supposed to represent B. acuto-rostrata, I am unable to speak with any great degree of confidence regarding the matter of identity in this case. The three specimens referred to are as follows:

(1) A skeleton 16 ft. 5 in. long from off Monomoy Pt. Lighthouse, Harwichport, Massachusetts, in the U. S. National Museum. (No. 20931, from the U. S. Fish Commission, 1883.)

(2) Measurements, description, and sketches of a female, 15 ft. 4 in., entangled in the nets of the fishermen near Portland, Maine, in July, 1893, and exhibited in that city. I owe the data relating to this specimen to Joseph P. Thompson, Esq., Vice-President of the Portland Society of Natural History.

(3) Two photographs of a female, 22 ft. 8 in. long, captured near Quoddy Head Life-saving Station, Maine, Sept. 6, 1889, and reported to the Smithsonian Institution by Capt. A. H. Myers, keeper of the station.

An imperfect skull was dredged up near Pigeon Cove, Mass., in 1881, and sent to the National Museum, by Mr. Wm. H. Jackson. It is not now accessible. (No. 23025.)

The sketch of the exterior of the Portland specimen (text fig. 51) shows that

FIG. 51.

FIG. 52.

BALENOPTERA ACUTO-ROSTRATA LAC. PORTLAND, MAINE.

FIG. 51.-FEMALE, LENGTH 15 FT. 4 IN. FIG. 52.-LEFT PECTORAL FIN OF THE SAME. EXTERNAL SURFACE. (FROM SKETCHES BY JOSEPH P. THOMPSON, ESQ.)

it corresponds with the diagnosis of B. acuto-rostrata as regards the general form, and in the form of the dorsal and pectoral fins. The color markings on the external face of the pectoral fin are exactly as in that species, as is shown by Mr. Thompson's excellent figure (text fig. 52). His notes on this specimen are as follows: "The color of the body was an ashy black above, passing into a pure white on the belly, without any distinct demarkations; nor was there any apparent lateral line. The blowhole was in a sunken cavity. The eye was very near the corner of the mouth. The number of longitudinal furrows could not be accurately counted, though they were very strongly marked, of a pinkish color within the folds, and white without. The baleen was of a pinkish brown at the bases of the plates and fading in color

« AnteriorContinuar »