1888 ] PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 309 



bone I have already figured in another connection. (Proc. U. S. Xat. 

 Mas., Vol. Vii, p. 327, P of Fig. E.) 



Torso metatarsus in Sula is strikingly large in its proportions when 

 compared with the other bones of the limb. In length it is a little 

 more than half as long as tibio- tarsus, but being wider and broader it 

 appears much more massive. (Fig. 36.) 



Its hypo tarsus presents three short, longitudinal elevations of un- 

 equal sizes. These inclose two tubular passages for tendons, and are 

 grooved themselves besides. The back of the shaft is flat, but in front 

 it is much scooped out above, where it shows two anteroposterior per- 

 forations. 



At the distal extremity three large trochlear projections present 

 themselves. They are separated from one another by wide clefts of 

 about an equal depth. These trochlea 1 are placed nearly side by side, 

 the middle one being the lowest down, the inner next, and the outer 

 one the most elevated. Their median grooves are best marked behind, 

 but in addition the internal trochlea presents a deep, vertical notch 

 upon its outer aspect. 



The usual arterial perforation pierces the bone above the cleft found 

 between the outer and middle projections, a groove leading in to it 

 from above. 



Accessory metatarsal is rather an elongated bone, swung to the 

 lower part of the shaft in the usual way by ligament. 



The basal joint of hallux, which it supports, is comparatively more 

 slender for its length than the other joiuts of the foot. 



These latter are in number and arrangement for the three anterior 

 toes the same as in the vast majority of the class. They present all 

 the characters usually attributed to the phalanges of the podal digits 

 in birds, and are well proportioned, both as regard their relative cali- 

 bers and lengths. 



NOTES UPON THE SKELETON OP PHALACROCORAX UEILE. 



Three or four years ago I published in u Science"' an account of the 

 osteology of this Cormorant, then called P. bicristatus. Professor Cones, 

 in his "Key" to North American Birds, second edition, did me the honor 

 to reproduce my figures from " Science," and I further added to them in 

 an article on the patella of birds, which appeared in the Proceedings 

 of the U. S. National Museum (Vol. VII, p. 325). Here I pointed out the 

 unusual characters of the patella as they were to be found in the Cor- 

 morants, and gave a front view of this sesamoid in P. urile. 



Cormorants are further noted for possessing, in common with Plotus, 

 an osseous nuchal style (Fig. .39, st. o.), occupying a position corre- 

 sponding to the ligameutum nucha' of most mammals. 



As in riotus, from either side of this freely articulated style of the 

 occiput the temporal muscles also arise. This little bone has been re- 

 marked upon by Owen, Brandt, Eyton, Garrod, and other eminent 



