206 Mr. F. E. Beddard on the Anatomy 



It is quite otherwise with the hind limb, which does, in its 

 muscular anatomy, exhibit characters of classificatory value. 

 Garrod* was the first to draw attention to the fact that the 

 Cuculidse can be divided into two series, in accordance with 

 the presence or the absence of the accessory femoro-caudal 

 muscle. In one series, which is represented by Ceniropus, 

 the muscle-formula of the hind limb is ABXY + , the " full " 

 muscle-formula; in the second series, of which the genus 

 Cuculus is an example, the muscle-formula is the reduced 

 one, AXY+. Thirteen years later t I extended this list to 

 a number of Cuckoos not examined by Garrod, all of which 

 proved to have either the muscle-formula ABXY + or the 

 reduced formula AXY + . : 



So far as I know, there have been no further observations 

 upon this subject. 



Naturally, therefore, one of the earliest points to which 

 I directed my attention in dissecting Carpococcyx was the 

 condition of the flexor muscles of the thigh. I found that 

 all the four muscles in question are present, well developed, 

 and conspicuous. So that Carpococcyx, like Scythrops, 

 Eudynamis, Phcenicophaes, Centropus, Geococcyx, Crotophaga, 

 and Guira, possesses the complete muscle-formula ABXY + . 



I shall not give a full description of the attachments and 

 insertions of these several muscles of the thigh, since they do 

 not appear to me to present any noteworthy peculiarities. 



As to other muscles, I may observe that the glutceus 

 maximus has a large postacetabular extension, which com- 

 pletely hides the biceps, except just where the latter ap- 

 proaches the biceps sling. 



Both the peroneus longus and the peroneus brevis are 

 present. 



f. The Skeleton. 



The skull of Carpococcyx (fig. 22, p. 208) is not widely 



* " On Certain Muscles of the Thigh of Birds," &c., P. Z. S. 1873, 



p. 626. 



I " On the Structural Characters and Classification of the Cuckoos," 

 P. Z. S. 1885, p. 168 ; and " On the Anatomy of an Australian Cuckoo 

 {Scythrops nov<e-hoUandice),'' ibid. 1898. p. 44. 



