I08 Shufeldt, Osteology of Harris s Cormorant. [,sf"oct 



" nutrient foramina," and not pneumatic ones, the bones of this 

 limb have an abundant vascular supply. 



In P. urile the femur, as compared with the one just described, 

 is relatively longer with respect to the average, and considerably 

 smoother and slenderer. For the size of the species, this like- 

 wise applies to P. aiiritus. The bone is especially smooth in P. 

 carbo (No. 18,851, Coll. U.S. Nat. Mus.) and in other species at 

 hand. In P. pnnctatus it is shortened and much bowed, almost 

 reminding us of the femur in some Grebes, though the femur 

 exhibiting the greatest amount of curvature belongs to P. 

 penicillatus (No. 18,535). 



The patella is very large, trihedral in form, with an extensive, 

 squarish base, moulded to receive in articulation the larger share 

 of the surfaces of the femoral condyles. Above its middle it has, 

 passing transversely through it, a good-sized foramen, which, on 

 the inner aspect, is at the base of a more or less circumscribed 

 concavity there ; while on the outer side it comes out about flush 

 with the surface of the bone. This foraminal passage transmits 

 the ambiens muscle, but I find it is not patulous in all Phala- 

 crocoracidce. Garrod, who studied it in P. carbo and in " P. 

 lugubris," remarks that " Meckel did not find the ambiens in the 

 Cormorant ; it is peculiar, in that it runs through the substance 

 of the large triangular patella, in a bony canal " (Coll. Sci. Mems., 

 footnote, p. 198). Possibly Meckel may have had a Cormorant 

 where the ambiens does not pass through the aforesaid bone ; 

 this is a matter I have not looked up. 



Patella; of Cormorants I have figured in a number of my 

 jmblished papers; one of these figures Coues used in his " Key" 

 (5th ed., vol. ii., p. 961, fig. 675, P. bicristatus), stating in the 

 text that, with respect to Cormorants, " There is a bulky free 

 patella, co-existent with a short cnemial apophysis or rotular 

 process of tibia, but perfectly distinct therefrom, as in Grebes." 

 Now, at the present writing, after having compared and studied 

 this big seasmoid in a good many Cormorants, I am convinced 

 that this statement is entirely erroneous. As to the patellae and 

 the cnemial process of the tibio-tarsus in Loons and Grebes, it 

 has been correctly described by numerous ornithotomists, 

 including myself. Coues, in the volume just cited, gives, on 

 page 1,052, a figure — one of my own, unacknowledged — of a tibio- 

 tarsus and patella of a Grebe. This is a correct drawing, and from 

 it will be observed that the cnemial process of the tibio-tarsus (a) 

 co-ossifies with and is a part of the latter, while the big, free patella 

 is in close contact with its posterior surface. As I have pointed 

 out in many places, the arrangement is quite different in the 

 Loons.* 



* Shuffklt. R. W., " Concerning the Taxonomy ol the North American 

 I^ygopodes, Based Upon their Osteology," Journ. Anat. and P/iys., London, 

 June, 1892, pp. 199-203. On page 202 it is stated, with respect to the 

 Loons (" Urinatoroidea") that they possess "only a very small, flake-like 

 sesamoid, which occurs in the tendon of the extensor femoris muscle at its 



