lines Length of sternum 13 Breadth anteriorly 6½ posteriorly 8½ Depth of keel 5 fissures 4 Breadth of ditto 1½ Length of pelvis 13½ Breadth anteriorly 5 posteriorly 10½ Length from occiput to point of bill 19 Breadth of cranium 8 Length of coracoids 10 No. of cervical vertebræ 11 dorsal ditto 7 sacral ditto 9 caudal ditto 6 ——— Total 33 ——— No. of true ribs 5 false ditto 2·1 ——— Total 8 Remarks:—the last five species approach so nearly, that I doubt the propriety of separating them generically. The skeletons are only distinguishable with the exception of the form of the bill, by the proportions between the different admeasurements. PTEROPTOCHOS TARNII. _G. R. Gray._ (Female.) Tongue pointed, armed with two strong lateral spines, and a few intermediate smaller ones at the base; œsophagus largest at the upper extremity, and gradually becoming smaller towards the proventriculus; no vestige of a craw; proventriculus of moderate size, not much contracted towards the gizzard, which is also of moderate size, and much flattened; not very muscular, and lined with a hardened coat, rugose longitudinally; the gizzard was filled with small pebbles, and a coarse black powder, probably the remains of insects; intestinal canal small; cæca rudimental; rectum large, becoming more expanded towards the cloaca, which is also large; trachea of equal diameter throughout, furnished with one pair of sterno-tracheal muscles, a portion of each of which is continued downwards to the upper rings of the bronchiæ, on which it expands; liver two-lobed.