6

should have the desmognathous' skull of the American vultures.

Psophia has seventeen cervical vertebra, of which the

last bears a rudimentary rib. Five dorsal vertebræ are ankylosed, there being two free ones behind. The sternum

FIG. 184.

STERNUM, PELVIS, &C., OF Psophia leucoptera (AFTER BEDDARD).

(fig. 184) is entire and unnotched; eight ribs articulate with it.

The atlas is notched for the odontoid process. From the fourteenth cervical vertebra to the third dorsal there are blade-like median hypapophyses. In front of the fourteenth the catapophyses nearly enclose a canal; they get further apart and die away anteriorly. The following table shows the number and character of the hypapophyses in various Grues:

The family Eurypygidæ contains but one genus and species, Eurypyga helias, native of South America. It has an oil gland, which is generally nude but occasionally tufted, and twelve rectrices. Eurypyga, like Rhinochetus and Mesites, has powder-down patches, but their arrangement is very different from those of Rhinochetus. Dorsally there is on either side of the dorsal tract a compact dense triangular patch; in front it continues over scapula as a band which runs on to the sternal surface, and there forms a sparsely feathered patch more or less continuous with pectoral tract of contour feathers. There are a few scattered powderdowns on axilla and along neck.

The tensor patagii brevis is broad and rather diffused, stronger at the two edges; it sends off a wristward slip. The tensor longus is reinforced by a strong biceps slip.

The expansor secundariorum is strong and ciconiine.' The anconaus has a humeral attachment. The insertion of the deltoid extends halfway down the humerus. I have noticed in the pectoralis primus a vertical septum dividing the muscle into a right and left half.

The muscle formula of the hind limb is complete, i.c. ABXY+. The gluteus I. extends well over the biceps. Both peroneals are present.

The liver is equilobed, with a gall bladder. The intestines are 18 inches long, the short cæca (inch) being 11⁄2 inch from cloaca.

Both carotids are present.

The skull of the sun bittern has been described 1 and figured by PARKER.

It presents several points of likeness to that of Rhinochetus, notably in the ardeine character of the palatines," which are cut off squarely behind and are of approximate length throughout; each palatine, moreover, has a fenestra, as in Tigrisoma leucolophum (and also in Numenius phæopus and Anous stolidus). The interorbital septum is widely fenestrate; there are no occipital foramina. As in Psophia (q.v.), Rhinochetus, and cranes, there is a rudimentary snag' from the anterior part of maxillo-palatine.

The nostrils are schizorhinal, and the curves of the various surfaces of the bones are such that if the very narrow anterior chink were closed a well-rounded and quite typical holorhinal skull would be the result.

Eurypyga has a one-notched sternum with well-developed spina externa. There are eighteen cervical vertebræ, and three dorsals are fused.

The pelvis is a little less rail-like than in Grus, Rhinochetus, Psophia, &c., in being wider, and in the more horizontal plane of ilia, which do not meet.

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Family Aptornithidae. The two species of Aptornis, A. defossor and A. otidiformis, from New Zealand quaternary deposits, were originally referred to the Dinornithidæ, and more lately to the rails. FÜRBRINGER has, however, advanced certain reasons for relegating them to the neighbourhood of Rhinochetus, and I follow him in placing them in the present group. The chief reason which persuaded FÜRBRINGER to this conclusion was the schizorhinal nostrils, quite evident

'On the Osteology of the Kagu,' Tr. Z. S. vol. vi., and On Egithognathous Birds,' ibid. vol. x. p. 307, pl. liv. figs. 7, 8, 9.

2 See, however, footnote, p. 373.

OWEN, 'On Dinornis,' pt. xv. Tr. Z. S. vii. p. 353.

in OWEN's plates,1 and showing the inward curvature so often found in the schizorhinal nostril, and quite apparent in Grus (though not in Rhinochetus). A special point of resemblance to Rhinochetus among the crane-like birds seems to me to be in the partial ossification of the nasal septum. The solidity, posteriorly at any rate, of the interorbital septum is like Psophia so far as gruine birds are concerned, while the spout-like process upwards of the palatines is quite in harmony with FÜRBRINGER'S views of the affinities of Aptornis. The junction of the zygoma with the post-frontal process is not crane-like; it occurs among gallinaceous birds, and there is a near approach to it in Otis.

In the view given by OWEN of the under surface of the skull is a bone described, though not figured, which appears to me to correspond to the desmognathous palate of Cariama. The union of the bones and their divergence posteriorly are precisely like what is to be seen in Cariama. Large basipterygoid processes are present, but OWEN failed to find upon them an articular surface.

So that while the outline of the skull of Aptornis is very like that of some of the large rails its affinities have been probably more correctly diagnosed by FÜRBRINGER.

Besides the Aptornithidæ already mentioned other forms referable to the Grues have been obtained from Tertiary strata. Of these Aletornis (with a number of species) is placed among the Gruidæ and Geranopsis of LYDEKKER. The latter is known only by the coracoid, which differs somewhat from that of Grus. LYDEKKER does not admit the genus Palæogrus of PORTIS.

The family Mesitidæ is represented by the Madagascar Mesites, a genus containing but a single species, which has been investigated anatomically by MILNE-EDWARDS2 and by FORBES. One of its principal characteristics was originally

Loc. cit. pl. xl. figs. 1, 2.

* Remarques sur le Genre Mesites,' &c., Ann. Sci. Nat. (6), vii., and in Hist. Nat. de Madagascar.

3 •

Description of the Pterylosis of Mesites,' &c., P. Z. S. 1882, p. 267.

discovered by E. BARTLETT, who found and described briefly the powder-down patches.

The bird has sixteen rectrices, and apparently--but there is some little doubt about the matter-a nude oil gland. The contour feathers have no aftershaft. There are five pairs of powder-down patches. The most anterior pair lie in the interscapular region, and are enclosed by the dorsal tracts. The second pair are upon the rump, the third pair at the commencement of the pectoral region; the fourth pair lie also on the ventral region, but posteriorly; the fifth pair, finally, are axillary. The number of these pairs is greater than in any known bird, and their definition and complete separation as distinct patches contrasts with the diffused arrangement characteristic of Rhinochetus and Eurypyga.

There are four apteria on the neck, since both dorsal and ventral tracts divide early. The dorsal tracts converge interscapularly, and then become much feebler, and are continued on to the Y-shaped posterior part of the tract. The ventral tracts cease altogether at the commencement of the pectoral region, but recommence behind the powder-downs. The outer branch is present, but is quite unconnected with the

main stem.

The muscle formula is complete, ABXY+. Both carotids are present.

AS FÜRBRINGER removed Aptornis from the rails and placed it in the present group largely on account of its schizorhinal nostrils, it is remarkable that he did not also do so with the present bird. The bony nostrils are, in fact, of the type that has been termed pseudo-holorhinal. They are rounded at their end, but elongated and curved inwards; they are exactly like those of Glareola.

Mesites is schizognathous, with delicate maxillo-palatines. The descending process of the lacrymal abuts upon, but does not fuse with, the very stout square éctethmoid. This part of the skull, again, is more like Glareola than any gruine form; but it is also like Pterocles and various other birds.

There are seventeen cervical vertebra, and four ribs reach 'Remarks on the Affinities of Mesites,' P. Z. S. 1877, p. 292.