ON THE ANATOMY OF NYCTIBIUS WITH NOTES ON 

 ALLIED BIRDS. 



By Alexander Wetmore, 

 Of the Biological Survey, United States Department of Agriculture. 



The sternum and foot of the genus Nyctibius have been described 

 by P. L. Sclater/ and an account of the palate was given many years 

 ago by Huxley ,2 but little has been published on the anatomy of 

 the soft parts of these birds so far as is known. Through the cour- 

 tesy of Dr. C. W. Richmond, acting curator in the Division of Birds. 

 United States National Museum, the writer has been permitted to 

 dissect the body, preserved in alcohol, of the type-specimen of the 

 Potoo described recently as Nyctihius gnseus ahhofti.^ This bird 

 (Cat. No. 225851, U.S.N.M.), a male, was collected by Dr. W. L. 

 Abbott at Port de Pimenti, northwest Hayti, on March 9, 1917. 

 Though this specimen comprised the trunk and viscera alone, several 

 points of interest were brought out by critical examination. An 

 account of the dissections made is given in the following pages. 



The esophagus was contracted, and in this state had strong thick- 

 ened walls, with the inner surface thrown into a series of longi- 

 tudinal folds or rugae that expanded anteriorly to join the broader 

 surface of the pharynx. Apparently the esophagus was capable of 

 great distension in life, and the bird must have been able to swallow 

 any object that could pass the opening guarded by the furculum and 

 the vertebrae at the anterior end of the body cavity. The proven- 

 triculus was large and glandular, and the stomach proper was com- 

 paratively thick walled and strong. This bird probably regurgitates 

 pellets composed of chitinous fragments of insects and other in- 

 digestible matter, as the pyloric opening of the ventriculus was too 

 small to allow particles of any size to pass. In the present instance 

 the stomach contained insect jaws and other fragments too large to 

 pass through into the small intestine and too firm in texture to 

 permit of trituration. 



1 Notes upon the American Caprlmulgldae, Proc. Zool. Sec. London, 1866, pp. 123-130. 

 » On the Classification of Birds, Proc. Zool. Soc. London, 1807, p. 454. 

 « Richmond, C. W., Descriptions of two new Birds from Haiti, Smiths. Misc. Coll., 

 vol. 68, No. 7, July 12, 1917, p. 1. 



PROCEEDiNGS U. S. NATIONAL MUSEUM. VOL. 54— NO. 2251. 



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