OCR Text |
Show 444 MR. W. A. FORBES ON T H E [May 16, towards their insertion, and dilated apically. There are two carotid arteries. In the leg, the ambiens and accessory femoro-caudal muscles are absent, as are the gluteus quintus and primus. The femoro-caudal, semitendinosus, and accessory semitendinosus are all well developed. Tbe myological formula is thus - A . X Y . The obturator internus is triangular. The deep plantar flexor tendons of the toes blend about three quarters down the leg, the slip to the hallux being given off from the inner of the two tendons a little before it joins the other one. The pectoralis secundus extends nearly to the end of the sternum. There is no third pectoral, nor biceps slip to the patagium. The expansor secundariorum muscle, on the other hand, is well developed, the long thin tendon ceasing on the axillary margin of the teres muscle in a way hitherto only known in some of the Gallinaceae1. I find, however, that exactly the same condition occurs in Momotus (lessoni) and Hylomanes {gularis), in some of the Alcedinidae (e. g. Fig. 1. Syrinx of Todus: A, from before ; B, from behind. Tanysiptera, Syma, and Cittura), as also in Steatornis. The presence of this muscle at all in these groups of birds was, I may remark, hitherto unknown2. The tensor patagii brevis at its termination has an arrangement almost identical with that of the Momotidae 3, only differing from it in the absence of the thin slip of fascia which is continued, in them, from the recurrent " passeriniform" tendon to the fascia covering the ulnar side of the forearm. The deltoid has no special tendinous slip of origin from the scapula. 1 Cf. Garrod, Coll. Papers, p. 324. Besides the Coraciidte, the existence in which of this muscle was pointed out by Garrod (Coll. Papers, p. 324), it exists also of the same " ciconiiform " shape in tbe Meropidse, Leptosoma (P. Z. S. 1880, p. 470), and, as already noted in M S . by Garrod, in the Galbulidte. It is absent in all (? Bucconidae) the other families of Anomalogonatae. 3 Cf. Garrod, loc. cit. p. 359. |