NO. 2251. 



THE ANATOMY OF NYCTIBIUS—WETMORE. 



585 



The relationships of the goatsuckerlike birds of the groups char- 

 acterized by the genera Podargics, Nyctibius, and Caprimulgus have 

 been interpreted in various ways by different authors. Sharpe^ 

 placed Podargus in a suborder Podargi of the Coraciiformes, while 

 he united Nyctibius^ which he considered as the type of a distinct 

 family, the Nyctibiidae, with the Caprimulgidae in another suborder, 

 the Caprimulgi. Beddard^ and Gadow^ on anatomical grounds 

 joined all these with Steatornis under one suborder known as the 

 Caprimulgi. 



Mr. Ridgway* in his recent treatment of the group has proposed 

 a suborder Nycticoraciae to include the super families Caprimulgi 

 (Caprimulgidae + Nyctibiidae), Podargi (Podargidae) and Steator- 

 nithes (Steatornithidae). 



The grouping of Steatornis^ Podargus and its allies, Nyctibius, and 

 the various genera belonging to the Caprimulgidae in one suborder 

 under the Coraciiformes is one that seems logical in view of the facts 

 known through modern research into the affinities of these birds. 

 Steatornis as an outlying aberrant form, though seeming to belong 

 to this suborder, is so different from the other genera included in the 

 Nycticoraciae that it is readily separated from them in a well cir- 

 cumscribed division, and may be dismissed without further comment. 

 A survey of the facts now known concerning the anatomy of Nycti- 

 bius, however, together with the structural characters of this genus 

 previously recorded, serve to show that the gap between the two re- 

 maining superfamilies recognized by Mr. Ridgway is less trenchant 

 and sharply defined than has been supposed. In the following table 

 are given the details of 12 of the main structural characters of use in 

 the classification of the members of this group remaining after 

 Steatornis is removed. 



Oil gland 



Powder down patches . . 



Carotid arteries 



Syrinx 



Left liver lobe 



Tongue 



Cervical vertebrae ...... 



Sternum 



Procoracoidal process. . . 



Basipterygoid processes 

 Palatines 



Number of phalanges in 

 fourth toe. 



Podargus. 



Absent 



Present 



One (left) 



Bronchial 



More than one-half as 



large as right. 

 Large, with transparent 



paperlike tip, spinose 



basally. 



13 



Four notched 



Large, reaching furcu- 



lum and scapula. 



Absent 



Broad throughout, 



slightly expanded 



posteriorly. 

 Five 



Nyctibius. 



Absent 



Present 



One (left) 



Tracheo-bronchial 



One-flfth as large as 

 right. 



Medium, shaped like a 

 spearhead, feebly pa- 

 pillate. 



14 



Four notched 



Small, not reaching fur- 

 culmn. 



Present 



Narrow anteriorly, 

 greatly expanded 

 posteriorly. 



Five 



Caprimulgidae. 



Present. 



Absent. 



Two. 



Traeheo-broncliial. 



One-tliird to one-half 



as large as right. 

 Small, triangular in 



outline, more or less 



spinose. 

 14. 



Two notched. 

 Small, not reaching 



furculum. 

 Present. 

 Narrow anteriorly, 



greatly expanded 



posteriorly. 

 Four-. 



1 Review of Recent Attempts to Classify Birds, 1891, pp. 79, 81. 

 « Structure and Classification of Birds, 1898, pp. 231-244. 

 » Classification of Vertebrata, 1898, pp. 36-37. 



* Birds of North and Middle America, Bull. 50, U. S. Nat. Mus., part 6, 1914, pp. 

 487-489. 



