MURIE, has been rather more fully dealt with by FORBES. The dorsal tract is double on the neck, and continues so until its termination about on a level with the scapula. The posterior portion of the dorsal tract is not continuous with the anterior portions; it terminates with a slight bifurcation anteriorly and is widely dilated mesially. The ventral tract is broken into two by the intervention of powder-downs, and the pectoral branch is perfectly separated from the main tract, a unique feature, save for Mesites. It is the scattered powder-downs which are apparently responsible for much of the breaking up of the pteryle of Rhinochetus.1 The semitendinosus, its accessory, the femoro-caudal, and the ambiens are all present in the kagu. As in Psophia and some other birds, the semitendinosus is inserted in common with the semimembranosus. The relations of the last muscles and of the gastrocnemius are illustrated in the accompanying figure (fig. 178), which will explain itself. Both peroneals are present, and have the typical arrangement seen when both muscles are developed. The deep plantar tendons are as shown in the figure (fig. 179). The flexor FIG. hallucis supplies the hallux alone, and is tied to the flexor communis by a strong vinculum before the trifurcation of the latter. The mode of insertion of the tensor patagii brevis is complicated; the tendon divides into three branches, the two inner of which are prolonged some way beyond the tendon of the extensor metacarpi radialis longi, to which they are first of all attached. There is a biceps slip.2 The anconaus longus has a flat tendon of origin from the humerus, as well, of course, as its scapular head. A muscle apparently peculiar to Rhinochetus (see fig. 180) is what has been termed by me an accessory biceps.' This arises

In his paper on Mesites, P. Z. S. 1882, p. 267.

179.--DEEP FLEXOR TENDONS OF Phinochetus (AFTER BEDDARD).

2 I wrongly asserted the absence of this in my paper upon the anatomy of the bird.

The

from the humerus just below the insertion of the deltoid, and is inserted near to the insertion of the biceps. expansor secundariorum is present.

The syrinx of Rhinochetus is tracheo-bronchial, and presents us with no features of special interest. The accompanying drawing (fig. 181) shows its lateral aspect. The bronchidesmus is incomplete; the intrinsic muscles are attached to the third bronchial semi-ring.

The number of cervical vertebra is sixteen. Four of the

last dorsal vertebræ are ankylosed. Five ribs articulate with the sternum. The sternum is unnotched. The skull is schizorhinal; there are no basipterygoid processes. There is a partial bony internasal septum not to be found in the cranes. The interorbital septum is more fenestrate than in

them. The palatines are abruptly truncated posteriorly, as in the herons. There are small occipital foramina.

An abnormal member of the crane 2 group is the South American seriema, of which it is usually considered that there are two genera, Cariama and Chunga, of the family Cariamida. These birds agree with the cranes

in possessing an aftershaft and in the number of their rectrices (twelve). The oil gland, however, is nude. In the pterylosis (which has been described by NITZSCH) there is a marked break between the posterior forks of the anterior section of the dorsal tracts and the anterior fork of the posterior section of the same tracts.

The dorsal tract is single on the neck and divides interscapularly. The posterior parts of the ventral tract are formed of two 7rows about two feathers wide. Each joins the outer branch above by one row of feathers merely.

The skull (fig. 182) is desmognathous, but the two maxillopalatines, though they come into contact in the middle line, are not fused.

The nasals are арра

R&H

rently holorhinal, really schizo- FIG. 182. SKULL OF Chunga rhinal (see p. 144), and there are no VENTRAL VIEW. (AFTER BEDDARD.) basipterygoid processes. There are fifteen cervical vertebra; five ribs articulate with the sternum, which is one-notched; it has the spina externa.

'Stress has been laid upon this fact and comparison, but a posterior truncation of the palatines, nearly as marked, is to be seen in Fratercula arctica and not in some other auks.

2 The skull is described by PARKER, Tr. Linn. Soc. (2), i. p. 128; the general osteology and to some extent the visceral anatomy by BURMEISTER,

The muscle formula of the leg is BXY+, as in bustards. The accessory femoro-caudal muscle (of Chunga) is peculiar in that it becomes reduced in the middle to a thin tendon, being muscular at both extremities. Both peroneals are present.

The tensores patagii spring from a single muscle. There is no biceps slip, another point of likeness to bustards. The brevis tendon spreads out into a broad aponeurosis, but there is no patagial fan. The anconaus has a humeral head. The intestinal measurements of the two birds are as follows:

The family Psophiida is represented by the single South American genus Psophia, including some four species. These birds have the outer aspect of a rail rather than of a crane, and PARKER has commented upon their phasianine expression of face. Nevertheless their nearest alliance seems to be with the crane tribe, and perhaps more especially with Cariama.

The pterylosis has been described and figured by NITZSCH. There are apparently ten rectrices (not twelve, as NITZSCH stated), and the oil gland, as in Grus, is tufted. The dorsal tract is single on the neck and forms a strong bifurcation between the shoulders; from the two ends of the fork a single row of feathers descend and unite to form a weakly feathered but widish posterior part of the dorsal tract. The ventral tract bifurcates early in the neck, and each in the pectoral region gives off a strong band on the outside; the main portion of each tract is continued on to the cloaca by

'Beiträge z. Naturgeschichte der Seriema,' Abhandl. nat. Ges. Halle, i. (1854), p. 17; the viscera also by GADOW, J. f. O. xxiv. (1876), p. 445, and by MARTIN, P. Z. S. 1836, p. 29. See also BEDDARD, 'On the Anatomy of Burmeister's Cariama,' P. Z. S. 1889, p. 594, and literature there quoted.

a very narrow band of feathers, which is only one feather wide to begin with, and afterwards only two feathers wide.

The tensor patagii muscles are distinctly gruine; the biceps slip is present.

In the hind limb the muscle formula is BXY+, as in Cariama and the bustards.

The syrinx, shown in the accompanying woodcut (fig. 381), presents no remarkable features. It is quite typically tracheo-bronchial, and has, as will be observed, an incomplete bronchidesmus. It has been stated

(by TRAIL) that the windpipe communicates with an air space, apparently after the fashion of the emu. But there is no doubt that this statement was based upon some imperfection of the example studied. It has been also stated that the windpipe in the male is convoluted; this requires confirmation also.

FIG. 183.-SYRINX
OF Psophia leu-
coptera (AFTER
BEDDARD).

The skull of Psophia' is schizognathous and holorhinal (fig. 81, p. 143). AS PARKER first observed, the orbital margin is furnished with about five smallish supra-orbital bones, a feature which reminds us of certain archaic birds, as the tinamous, Arboricola, and Menura. The lacrymal has a descending process, which is swollen and nearly comes into contact with the ectethmoid. The maxillo-palatines are comparatively large and swollen bones; as in Cariama these bones are convex on the outer side, and not concaveas in Grus. There are no occipital foramina. It may be remarked that the holorhinal nostrils of this bird show no such approach to schizorhiny as is displayed by Chunga.

From the anterior part of the maxillo-palatines, on a level with a point just in front of the commencement of the bony nostrils, a stoutish knob of bone 2 projects inwards on either side. Of this there are traces in the cranes, particularly in Tetrapteryx. If these processes were to be increased in size and to meet a bony internasal septum, we

1 F. E. BEDDARD, 'On the Structure of Psophia,' &c., P. Z. S. 1890, p. 329. 2 Duly referred to by PARKER, Osteology of the Kagu,' Tr. Z. S. vi. p. 507.