10 PROCEEDINGS OF THE NATIONAL MUSEUM • vol. 74 



to a distance equal to the vibrissal axis. Palpi a little elongated and 

 slender, not clavate. 



Thorax yellow in ground color except the median part of the 

 mesonotum. The best preserved specimen shows the following 

 chaetotaxy: Acrostichal 1.0; dorsocentral 2,2; humeral 2; post- 

 humeral 1; presutural 1; notopleural 2 (the posterior hairlike): 

 supraalar 2 (posterior hairlike); intraalar 2; postalar 1; scutellum 

 with only two pairs of laterals, no apical or discal ; sternopleural 2,1. 



Abdomen very slender, the first segment entirely yellow, the second 

 with a lateral black spot on each side at the hind edge, and one 

 above including the median marginal bristles; third and fourth 

 segments narrowly bordered with black l)ehind, in one specimen the 

 dark markings extend forward on the middle of the dorsum of the 

 second and third segments and there are three minute spots on the 

 hind edge of the fii-st segment. First abdominal segment with no 

 median marginals, one pair of lateral marginals and two or three 

 smaller bristles before the latter. Second segment with one pair 

 lateral; third and fourth segments with a marginal row of about 

 six. The genital segments are small, entirely yellow, the inner for- 

 ceps yellow, combined into a minute, sharp point turned a little back- 

 ward; the outer forceps are also entirely yellow, considerably 

 elongated, stout at base, the slender apex curving inward and back- 

 ward. 



Legs yellow, the hind femora very slightly infuscated toward the 

 tip, the hind tibiae more or less infuscated; the tarsi brown, front 

 ones paler at base ; all the tarsi are decidedly elongated, much longer 

 than their tibiae. The front tibiae and tarsi measure 52 and 99 

 micrometer units respectively, the latter including 9 for pul villi. 

 All the claws and pulvilli much elongated. 



Wings slightly brownish, long and narrow, the costa with lui- 

 usually coarse and rough looking hairs as far as the end of the first 

 vein ; fourth vein with a long, oblique curve at the bend, toward the 

 tip a little concave, ending just before the apex; first posterior cell 

 rather narrowly open, but its apex not abruptly narrowed. First 

 vein bare, second with about three bristles at base. Calypters light 

 brown, translucent. 



Length, 8-8.5 mm. 



A badly preserved male from Tabasco, Mexico, in the United 

 States National Museum collection, was identified as cothumufa by 

 Townsend. It agrees very well with the type as far as can be judged 

 except that the costa has only the ordinary smooth setules. No 

 females have been seen which could be definitely associated with 

 cothinmata. One of the type males is retained by permission of the 

 Vienna museum. 



