194 NEOTROPICAL PSELAPHIDAE 



Abdomen with five tergites visible, the first very long as usual and with 

 discal striae as in chichion. Five visible sternites clearly visible (combined 

 median length 0.381 mm.) ; first stemite long (0.268 mm.), apical margin pro- 

 duced in median third of width to partially cover second; second, short; third, 

 produced into a sharp cusp at middle of apical margin, this tooth partially 

 covering the fourth; fourth, short and simple; fifth (terminal) longer than the 

 preceding three united, punctulated, apical margin broadly produced to fit 

 concave apical margin of fifth tergite. 



Mesostemum, intermediate coxae, posterior coxae, sternal foveae, meta- 

 episternal and associated sutures and the metasternum as in chichion. 



All tibiae normally slender at base, slightly thickened apically, bearing the 

 usual setose area apically at ventral face ; posterior tibiae slightly arcuate dis- 

 tally as usual. Anterior femora swollen dorsally, the swelling bearing a trans- 

 versely oval depression on the dorso-posterior part of swelling, this depression 

 punctulate-granulate and its dorsal edge strongly carinated as illustrated. Inter- 

 mediate femora complexly excavated and armed as illustrated. Posterior femora 

 simple. 



Allotype Female. As for holotype and paratypes save that (1) the distal 

 margin of labrum is less concave, (2) third visible stemite not medianly cusped, 

 (3) apical margin of fourth and basal margin of fifth sternites involved in a 

 small but distinct median depression, (4) fifth stemite with apical margin less 

 convex, nearly straight but more definitely punctate than in the male. 



Described on thirteen specimens all collected on Barro Colorado Island, 

 Qatun Lake, Panama Canal Zone, at lights at night. Paratype female May 19, 

 1935, by Alfred Emerson. Paratype male August 31, 1935, by Alfred Emerson. 

 Paratype males on July 6, July 7, July 14, July 15, 1936, by author. Holotype 

 male and allotype female on July 7, 1936, by author. 



Subgenus Decarfuss new subgenus 



Group XV of Raffray, 1904. Characterized by the front between the an- 

 tennae being produced into a long, conical and spiniform horn, directed an- 

 teriorly. 



Key to the Males of Group XV 



Antennae simple monoceros 



Antennae very abnormally formed as described 



euspinifrons new species 



Decarthron euspinifrons new species 



Holotype Male. Measurements: Head 0.234 x 0.361 mm. through the eyes; 

 pronotum 0.321 x 0.375 mm.; elytra 0.53 x 0.602 mm.; abdomen 0.335 x 0.556 

 mm. from a dorsal view; total length 1.48 mm.; greatest width 0.602 mm. 

 (PI. XVIII) 



