Inches Length of œsophagus, including proventriculus 2¼ gizzard ⁶⁄₈ Breadth of gizzard ½ Length of intestinal canal from gizzard to cloaca 7 Skeleton similar in form to _Furnarius cunicularius_, and the other species of this genus. lines Length of sternum 11 Breadth anteriorly 6 posteriorly 7½ Depth of keel 4¾ of fissures 4 Breadth of ditto 1¾ Length of pelvis 12 Breadth anteriorly 3¾ posteriorly 10½ Length from occiput to point of bill 18 Breadth of cranium 7½ Length of coracoids 9 No. of cervical vertebræ 11 dorsal ditto 7 sacral ditto 12 caudal ditto 7 ——— Total 37 No. of true ribs 5 false ditto 2·1 ——— Total 8 OPETIORHYNCHUS PATAGONICUS. _G. R. Gray._ (Male.) No difference in the structure of the soft parts from the other species of the genus before spoken of. The trachea, however, does not differ from the ordinary simple form found in most birds, but differs from _O. vulgaris_ and _O. antarcticus_, in having the lower rings continued to the bronchiæ it is acted upon by one pair of muscles; no cæca are apparent. Inches Length of œsophagus, including proventriculus 2⅛ gizzard ½ Breadth of gizzard ⅜ Length of cutis from gizzard to cloaca 5½ Skeleton in form similar to that of _Furnarius cunicularius_, and the other species of this genus.