1001.] SHUFELDT — OSTEOLOGY OF THE CUCKOOS. 31 



Proc. U. S. Nat. Mas., Vol. vii, 1884, p. 324.) Upon carefully 

 re-examining this material at the present writing it certainly seems 

 that this is the case, but I would prefer to microscopically investi- 

 gate a series of these bones of all ages and properly stained before 

 restating the opinion. 



In Geococcyx the proximal end of the ti bio-tarsus appears to pos- 

 sess a terminal epiphysis, something similar to what we see in the 

 Frog, and to this is super-added the additional piece, as already 

 stated above ; and as age advances in the individual the proximal 

 third of the shaft, so much larger than it actually is in the adult, 

 becomes gradually absorbed so in time to be equal to it in size. 

 (See PI. I, Fig. 6.) This is very curious. The lower two-thirds of 

 the bone in the young has a calibre proportionately less than the 

 corresponding part in the adult and is in harmony with the size of 

 the bird. 



I regret to say that ossification had proceeded so far in this 

 specimen that I was unable to determine anything beyond the 

 single segment at the distal extremity of the bone, and additional 

 material is required for me to decide whether or no the intermedium, 

 as described by Morse, develops in Geococcyx as a separate ossicle , 



In this young bird the pelvis already exhibits all of those peculiar 

 features, which makes it so interesting a subject for study in the 

 adult, while points of somewhat minor importance are to be noted 

 in other parts of the skeleton. The anterior half of the sternum is 

 quite complete, and all in one piece, while its posterior portion is 

 entirely in cartilage, and as yet gives no hint as to the form it will 

 eventually assume — even the xiphoidal prolongations not being 

 indicated. 



On the Osteology of Crotophaga. 



Through the courtesy of the U. S. National Museum I have the 

 following osteological material before me to illustrate the skeleton 

 in this extraordinary genus of Cuckoos, representing as they do the 

 subfamily Crotophagince.. First, nearly a complete skeleton of C. 

 sulcirostris (No. 6467) ; the sternum, shoulder-girdle and ribs of a 

 specimen of C. rugirostris (No. 7048) ; finally, the same bones from 

 a skeleton of C. ani (No. 432, Bryarth coll.). (See PL II, Figs. 8, 

 9 and 11.) 



In some few particulars there is a curious resemblance between 

 the lateral view of the skull of Crotophaga and the same view of the 



