378 Annals of the Carnegie Museum. 



but very slightly bowed anconad-wise ; its shaft is smooth, and for the 

 most part trihedral upon section. Papillje for the quill-butts of the 

 secondary feathers of the wing are but faintly in evidence, the first 

 five or six proximal ones being best marked. At the extremities the 

 usual articular facets for the humerus, radius, and ulnare are present, 

 and to all appearances the bone is a pneumatic one. 



A radius is a very slender and very straight bone; it has an average 

 length of 8.55 cms., and presents the usual ornithic characters found 

 in the Petrels generally at either of its extremities. 



No specimens of the two bones of the carpus — the radiate and 

 ulnare — are found in any of these collections ; but it is fair to presume 

 that they agreed in all essential particulars with the corresponding 

 elements in the wrists of typical Petrels generally. 



As in the case of the long bones of the brachium and antibrachium. 

 the main bone of manus — the carpometacarpus — is found to vary in 

 length, and for similar reasons. Upon measuring a series of them, 

 they seem to stand between 4.2 and 4.35 centimeters in this respect 

 (PI. XXVI, figs. 65, 66). The main shaft is straight and subcylin- 

 drical in form, being longitudinally grooved down its palmar aspect 

 for tendinal passage, which groove is best marked distally. Shaft of 

 medius metacarpal is almost parallel to the last described, but only 

 •about one-fifth its caliber. It is transversely compressed for its entire 

 length, and gradually enlarges as it coossifies with the distal extremity 

 of index metacarpal. This bone likewise has all the appearance of 

 -being a pneumatic one ; but I have failed to discover, with absolute 

 ■ certainty, the foramina to substantiate it. They are probably very 

 jninute and at the proximal extremity. 



vOn Plate XXVI (figs. 71, 72) I give two views of the proximal 

 plialanx of index digit, which shows its narrow expanded portion, 

 endmg distally in a distinct, outstanding little process, with another 

 nearly as prominent at the opposite side of the distal articulation. 

 This expanded part has a very thin, sharp edge or margin posteriorly, 

 while the anterior surface of its shaft is fiat. 



Several terminal digital phalanges occur in these collections, and I 

 have also figured them on Plate XXVI (figs. 75, 80-82). They pre- 

 sent, with their trihedral shafts, pointed distal extremities, and proxi- 

 mal articular ends, nothing worthy of detailed description; though, 

 doubtless, were one to compare a sufficient series of these bones with 



