1888.] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 260 



joint, and this of course applies to the common Fulmar, of which there 

 is an excellent ligamentous skeleton at hand. 



The shaft of the ulna shows faintly the row of osseous papilla; for the 

 quill-butts of the secondaries. So straight is the shaft of the radius that 

 scarcely any interosseous space occurs between these antibrachial bones; 

 such as it is, however, is long and narrow, extending between the shafts 

 for their full length. 



Carpus is composed of the two usual segments, and carpo-metacarpus 

 is formed much as we find it in the Laridw. Pollex phalanx and the 

 distal phalanx of the index are slender and subtrihedral and both strik- 

 ingly long. 



The expanded portion of the proximal joint of index digit is not per- 

 forated, as in mauy Gulls, and the small joint next to it is about half as 

 long. 



Excepting the great difference in size the pelvic limb of this Fulmar 

 nearly agrees with the pelvic limb of Oceanodroma. We observe that 

 the head of the femur is very much scooped out for the ligamentuum teres 

 and that the muscular lines mark its shaft pretty well. The patella 

 and oddly-shaped head of tibio-tarsus I have already figured elsewhere. 

 (Proc. U. S. Nat. Mus., 1883, Vol. vi, p. 329, Fig. 5.) I know of no bird 

 where the suppression of the ectocnemial ridge at the proximal end 

 of the bone and the high development of the procnemial ridge is better 

 shown. 



-The fibula is almost thread-like below its middle articulation with the 

 greater leg-bone, and its lower extremity anchyloses with its shaft. 



In the tarso-metatarsus the hypotarsus is doubly grooved behind, but 

 otherwise the arrangement of the accessory metatarsal and podal digits 

 is essentially the same as described for the Petrels. 



OSTEOLOGICAL POINTS WHEREIN OCEANODROMA FURCATA AND FUL- 

 MARUS GLACIALIS RODGERSII DIFFER. 



1. Oceanodroma. — Maxillojugal bar bent upward at an angle to meet 

 the descending process of lacrymal. 



1. Fulmarus. — Maxillojugal bar nearly straight. 



2. Oceanodroma. — Crotaphyte fossa? lateral, feebly impressed, not pro- 

 duced to meet the occipital prominence behind. 



2. Fulmarus. — Crotaphyte fossa? extended to the posterior aspect and 

 upon the occipital prominence; deeply impressed. 



3. Oceanodroma. — Maxillo-palatines do not encroach upon the inter- 

 palatine space. Vomer long and narrow, hinder half concave above, 

 correspondingly convex below and longitudinally grooved ; anterior 

 half carinated below, pointed in front and its concavity above continu- 

 ous with that of the posterior half. 



3. Fulmarus. — Maxillo-palatines do encroach upon the interpalatine 

 space. Vomer very large, nearly flat, broad, and general outline elongo- 

 cordate. 



4. Oceanodroma. — Basi-pterygoid processes entirely absent. 



