20 PROCEEDINGS OF THE NATIONAL MUSEUM vou 67 



forms examined. The anterior end of the hyoidean apparatus forms 

 a thickened, pointed projection in the tongue base. * * * Ante- 

 rior to this strong base the tongue is thin and translucent, being not 

 much thicker than a sheet of ordinary writing paper." 



Steatomis caripensis shows a "tongue shaped like an arrowhead, 

 with rather elongate, bluntly pointed tip, convex lateral outlines, 

 and spreading, somewhat slender posterior processes that project 

 beyond the hinder border. The margins of these posterior processes 

 are armed with soft, slender, backward projecting papillae, and 

 smaller papillae of the same nature are found on the upper surface 

 of these projections." 



The tongue of Phalaenoptilus nitidus " is small, measuring 9.5 mm. 

 long by 3 mm. broad. The postero-lateral spinose processes are 

 elongate and pointed. The lateral margins in outline are approxi- 

 mately straight lines. Spinose backward projecting papillae begin 

 at a point anterior to the center and become stronger and heavier 

 toward the base of the tongue. The upper surface of the tongue for 

 its basal two-thirds is thickly set with small horny papillosities all 

 projecting backward. Because of the posterior elongation of the 

 lateral processes, the basal margin appears deeply incised." 



This is the general form of the remaining genera of the Capri- 

 mulgidae. The tongue of Chordeiles virginianus is described as 

 showing a "slightly different development. This organ in the 

 nighthawk is small in comparison to the size of the mouth opening, 

 but is strong and heavy. It measures approximately 9 mm. long by 

 4.7 mm. broad at the base, so that it is short and broad in comparison 

 with the lingual appendages of other genera in this family that have 

 been described. * * * jj^ outline the tongue of Chordeiles virgin- 

 ianus is triangular with the lateral margins slightly concave. * * * 

 The lateral margins of the tongue are armed with spinose papillae 

 which are small and weak anteriorly and become strong and heavy 

 toward the base. Stronger processes arm the posterior margin, and 

 the broadened basal third of the tongue has its dorsal surface cov- 

 ered with pointed harsh papillosities all directed toward the 

 pharynx." With this description the tongue of Chordeiles acuti- 

 pennis texensis (fig. 81) agrees, with the exception that there are 

 no papillosities on the dorsal surface. 



The tongues of Nyctidromus albicolUs, Caprimulgus europaeus, 

 and Setochalcis vocifera are described by Wetmore as resembling in 

 form that of Phalaenoptilus nitidus, while that of Chordeiles acuti- 

 pennis is like that of C. virginianus. 



It can thus be seen that there are considerable differences mani- 

 fested in this group not easy of explanation and which do not give 

 any important information as to affinities. 



The Cypselidae do not show any striking tongue characters. In 

 some forms there is a close resemblance to tongues of swallows, as 



