Inches
Length of œsophagus, proventriculus included
        of gizzard⁶⁄₈
Breadth of ditto½
Length of intestinal canal from gizzard to the cloaca
        from cæca to cloaca

Skeleton similar in form to that of Furnarius cunicularius.

lines
Length of sternum11¾
Breadth anteriorly
        posteriorly
Depth of keel
      of fissures5
Breadth of ditto
Length of pelvis12²⁄₄
Breadth anteriorly4
        posteriorly
Length from occiput to point of bill17
Breadth of cranium7
Length of coracoids
No. of cervical vertebræ11
        dorsal ditto7
        sacral ditto11
        caudal ditto7
Total36
No. of true ribs5
        false ditto2·1
Total8

OPETIORHYNCHUS ANTARCTICUS. G. R. Gray. (Male.)

Structure of the soft parts as in O. vulgaris, but with the rectum of rather larger diameter, and the cæca very minute; gizzard filled with the remains of insects.

Inches
Length of œsophagus, including proventriculus
        gizzard⁶⁄₈
Breadth of gizzard½
Length of intestinal canal from gizzard to cloaca7

Skeleton similar in form to Furnarius cunicularius, and the other species of this genus.

lines
Length of sternum11
Breadth anteriorly6
        posteriorly
Depth of keel
      of fissures4
Breadth of ditto
Length of pelvis12
Breadth anteriorly
        posteriorly10½
Length from occiput to point of bill18
Breadth of cranium
Length of coracoids9
No. of cervical vertebræ11
        dorsal ditto7
        sacral ditto12
        caudal ditto7
Total37
No. of true ribs5
        false ditto2·1
Total8

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.