196 NEOTROPICAL PSELAPHIDAE 



Ventral surface of head with a deep, ovate fossa with carinated edges 

 typical of the genus. 



Pronotum with basal margin strongly beaded, the bead continuous, flat and 

 expanded anteriorly at middle into a blunt, triangular cusp. Median fovea free, 

 nude, sharply cut. A deep, pubescent lateral fovea each side at bottom of an 

 ovate depression. 



Elytra each with the usual two basal, nude foveae, entire sutural stria and 

 discal stria. The discal stria extends slightly beyond the middle of elytral length 

 (0.288 mm.). No subhumeral fovea and flanks lacking stria or carina. 



Wings well-developed. 



Abdomen with five tergites. First tergite long, strongly and narrowly mar- 

 gined, with two strong, slightly divergent, straight discal striae; these striae 

 separated by one-half the segmental width, and one-half the segmental length. 

 Five visible sternites. First morphological stemite invisible, covered by meta- 

 stemum and coxae but can be seen by dissection to be a narrow, very transverse 

 plate medianly, this plate punctate. First visible stemite (second morphological) 

 recessed each side to hold a posterior coxa, each coxal depression densely pu- 

 bescent, the segment very long (four times as long as other sternites united, 

 e.g. 0.268 mm.) with apical margin medianly produced to cover the second and 

 most of the third visible sternites; fourth stemite narrow; fifth (terminal) 

 stemite twice as long as fourth, distinctly punctate, apical margin strongly pro- 

 duced to fit the subacutely concave apical margin of fifth (terminal) tergite. 

 First visible stemite flattened medianly and last stemite tumid medianly. 



Intermediate and posterior coxae, mesostemum, sternal foveae, metaepi- 

 stema and associated sutures as in chichion. 



Metasternum medianly clothed with appressed, posteriorly-directed setae; 

 medianly tumid and this raised area flattened and the center of the flattened 

 area longitudinally sulcate. This sulcation is not deep but is clearly defined as 

 the consequence of two striaform sulci. Each sulcus arises near one of the fifth 

 sternal foveae, courses in an arc medianly, then laterally to end near each 

 stemal-metacoxal border. 



Anterior and intermediate trochanters with posterior face strongly flattened 

 to form an ovate table ; this tabular surface has a ctenoid appearance because 

 of a single row of equally long, closely set, stiff setae. 



Femora nornial, neither swollen, excavated nor armed. 



Anterior tibiae with the distal half of ventral face flattened and bearing a 

 pad of short setae. Pubescence of the distal fourth to sixth of the ventral tibial 

 face is typical for Decarthron but in euspinifrons the anterior tibial pubescence 

 is quantitatively exaggerated. 



Intermediate tibiae with a strong, lamelliform tooth, one-fourth as long 

 as tibia, arising from the ventral face at apical three-fourths. 



Allotype Female. Similar to holotype save that (1) front is simply decliv- 

 ous and simply formed, (2) first antennal segment simple, (3) second and third 

 visible stemites clearly discernible because the first visible is not so produced 



