| OCR Text |
Show 1896.1 ANATOMY OF 7ECHMOPHORUS MAJOR. 543 biceps of other birds. The coracoidal part of the muscle again divides into two parts, of which one supplies the radius, and the other the ulna. Dr. Gadow mentions, upon the authority of Meckel, that in Himantopus and Scolopax the biceps is divided. I find in a specimen of Himantopus nigricollis the following arrangement of the several parts of this compound muscle. The muscle has two distinct portions-one, which may perhaps correspond to the entire biceps of other birds, has the two normal heads, one arising from the humerus, the other from the coracoid. In addition to this is a distinct coracoidal portion which has a common origin from the coracoid with the coracoidal half of the double head of the muscle. In Cursorius I also found the biceps to be double much in the same way : but the division only commenced a little way below the level of the humeral attachment. Finally, in Lobivanellus there wTere indications merely of the same division by a superficial furrow extending for some way up the muscle. In the Gulls proper (the Larince of Howard Saunders) there is a syrinx of a more typical form than in any Limicoline bird known to me. Its more " typical" character consists in the fact that the single pair of intrinsic muscles are attached to the first bronchial semiring, and that that ring is bowed and closely attached to the last of six or seven slightly modified tracheal rings. In the Limicolae, on the other hand, the intrinsic muscles are frequently absent (Himantopus, Hcematopus, Squatarola), and when present do not as a rule extend clown as far as the bronchi; they end upon a tracheal ring at a variable distance from the end, though in some cases at least they may be continued as far as the bronchi by fibrous tissue. Lestris, however, has a syrinx which differs from that of the Gulls in that the intrinsic muscles end at the last tracheal ring, being attached partly to this and partly to the two in front; the muscle, in fact, is inserted rather obliquely. N o very distinct line can therefore be drawn between the two groups in the structure of the syrinx. Some justification for the association of the Laridae with the Alcidae is to be found in the disposition of the tendons of the tensor patagii brevis. In the Gulls, as in Limicoline birds generally, the tendon of tbe brevis muscle is double from the commencement, while the anterior of its two parts gives off just before its attachment a wristward slip from which passes upward obliquely the patagial fan to be inserted on to the tendon of the longus. There is, too, in both groups invariably a biceps slip, which may be inferred from Prof. Fiirbringer's statement: as, however, I a m acquainted, from my own dissections and from the sketches left by m y two predecessors, with a larger series of both Laridae and Limicolae than were known to Dr. Fiirbringer, the fact seems to be worth emphasizing. In Lanis argentatus there is, as is shown by a sketch of Mr. Forbes's, a peculiar tendinous slip passing from the tendon of the longus patagii to the flexor side of the forearm, which is quite distinct from the patagial fan already referred to. This has not been observed in any Limicoline birds but Charadrius pluvialis; it is highly characteristic of the Alcidae. It may therefore be useful to |
