19 o 5 .] ANATOMY OF PHAL.ENOPTILUS, RIDGWAY. 



235 



VII. Comparisons. 

 Certain characters of the better known genera of the Caprimul 

 gidas are compared in the following table : 



The sign "x" denotes occurrence, and " — " absence of a 

 character. The formulae for the thigh muscles are those given by 

 Garrod (1S74), slightly modified by Gadow (1891), and denote 

 the presence of the following muscles : 



Pars caudalis m. caud.-il. femoris , = A 



Pars iliaca m. caud-il. femoris =B 



M. caud-il. flex, inserting only on the tibia = X 



M. caud-il. flex, with the " accessorius " inserting on the 



femur — Y 



All the points of comparison of the first four genera in the above 

 table were taken from Beddard (1898). It will be noticed that 

 the amount of difference in these forms is slight. The only char- 

 acters which differ are the gall bladder, absent in Chordeiles, biceps 

 slip, absent in Phaloznoptilus, and the difference in the last genus 

 of the muscle formula for the thigh. 



So far as the tabulated characters are concerned, Phalcenoptilus 

 appears less closely related to Chordeiles than to the other genera. 

 In two of its muscle characters it differs from all the other genera. 



VIII. Aberrant Characters. 



In closing it will be well to call attention to the striking varia- 

 tions from the muscles of the birds studied and described by 

 Gadow (/. r.). 



The following wing muscles were not found: Biceps slip, m. 

 extensor policis brevis, m. entepicondylo-ulnaris and m. deltoi- 

 deus minor. Some not mentioned by him were present in the 



