Vol. XXVIII, pp. 175-176 November 29, 1915 



PROCEEDINGS 



OF THE 



BIOLOGICAL SOCIETY OF WASHINGTON 



AN ANATOMICAL NOTE ON THE GENUS CHORDEILES 



SWAINSON. 



BY ALEX WETMOKE. 



Mr. F. E. Beddard * in 1886, quoting a manuscript note 

 left by Professor Garrod, stated that the genus Chordeiles pos- 

 sesses no gall bladder. Two years later Dr. R. W. Shufeldtt 

 in comparing Chordeiles with Antrostomus says that ^^Antrosto- 

 mus possesses a small gall-bladder, while the several species of 

 Chordeiles lack this organ." Still later Beddard t again stated 

 that Chordeiles possesses no gall bladder. Following these 

 authorities Mr. H. C. Oberholser § used the lack of a gall 

 bladder as one of the minor characters upon which he founded 

 the family Chordeilidee. 



Bearing these statements in mind, I was interested in exam- 

 ining critically such individuals of the genus Chordeiles as came 

 into my hands. The dissections made by Garrod and by Shu- 

 feldt, recorded above, may have been made upon specimens of 

 nighthawks that were poorly preserved, as on opening a speci- 

 men of Chordeiles virginianus, killed near the mouth of Bear 

 River, Utah, during the past fall, I found a distinct receptacle 

 for bile developed in the right hepato-enteric duct and later 

 found the same condition in two additional specimens. 



As is the case in other related forms the right lobe of the 

 liver is the larger in the nighthawk. On raising this lobe 



*On the Syrinx and Other Points in tlie Anatomy of tlio Caprirnnlgidiie, P. Z. S., 

 1886. p. 151. 



i Studies of the Jlacroehires, Jlorpliological and Otherwi.se, Linn. Jour.-Zool., Vol. 

 XX.188S. p. 317. 



X .^tnic'ture and Classification of Birds, London, 1898, p. 234. 



$ Monograph of the Genus C'hordeiles Swainson, Type of a New Family of Goat- 

 suckers, Bull. 86, U. S. N. M., 1911, p. 9. 



37— Pkoc. Broi,. Soc. Wash., Vol. XXVIII, 1915. (175) 



