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Show 1880.] ANATOMY OF PASSERINE BIRDS. 383 Both the species under discussion agree entirely with Psarisomus and Serilophus in the points already noted by Prof. Garrod. I may add that the pectoralis prim,us is large, as is also the pectoralis secundus, this muscle extending to the end of the sternum, or thereabouts. As in other Passeres, the biceps-sho to the patagium and the expansor secundariorum are absent. The semimembranosus is slender, but muscular. The gluteus primus is large, covering the biceps; and the obturator internus is elongatedly oval. As will be seen in fig. 1, in Cymbirhynchus the vinculum in the deep plantar tendons is strong, and has the character of a firm round tendon, instead of being composed of more or less transversely-directed fibres running between the two tendons, as in many birds where this structure obtains. In Euryleemus ochromelas it is apparently double, there being a second additional slip given off lower down from the hallux-tendon, which joins the tendon of the digital flexor at the point where the latter, splitting up into three, receives the main vinculum. As regards the alimentary canal of these birds, there is nothing unusual in its conformation. The tongue is elongatedly cordate, and slightly bifid at the tip. Both it and the palate generally are smooth ; along its posterior sides^ it is provided, as is frequently the case, with about eighteen small, backwardly directed, spiny processes, that at the angle being much larger than the others. There is no crop developed; and the proventriculus is zonary : in Cymbirhynchus it is |-, in E. ochromelas A inch in vertical depth. The stomach has the character of a not very muscular gizzard, and is lined with hardened brown epithelium; the left lobe of the liver is the smallest (considerably). The caeca are present, as might have been predicted from the nude oil-gland1, and are truly Passerine in nature, being mere nipples g, or, in the smaller species, y1^ inch long. The following are the intestinal measurements :- Cymbirhynchus. Small intestine 7 fin., large intestine \\, total 9 in. E. ochromelas. „ 5-J „ „ f, „ 6^ in. The nature of the syrinx was the most interesting question to be examined in these specimens, Muller's short allusion to that of Corydon, quoted above, being all that was known as regards its structure. In Euryleemus ochromelas the syrinx is less specialized, as regards its cartilaginous constituents, than in Cymbirhynchus, and will therefore here be described first. The tracheal rings have their usual complete form, being notched before and behind to varying extents, and separated only by narrow intervals. The strong stemo-tracheales, the only extrinsic syringeal muscles, are inserted on the last ring but five. Only the last two tracheal rings are modified. The penultimate ring is narrowed and slightly produced downwards in front; the last is also narrow, and closely apposed to the penultimate, the membranous interval between the two being very much reduced, except in the middle line in front, 1 Cf. Garrod, P. Z. S. 1874, p. 119. |