1921] NATURAL SCIENCES OF PHILADELPHIA. 259 



tegmina are reduced sufficiently to leave exposed the distal portion 

 of the abdomen, Imt in that race these organs narrow to the rather 

 sharply rounded apices. In mesemhrina the tegmina are truncate 

 distad, the costal margin rounding very broadly into the transverse 

 distal margin, so that these organs leave almost the entire dorsal 

 surface of the abdomen exposed. 



Though apparently nearest lutea minima, the present species is 

 seen to approach that race only in features governed by reduction 

 in the organs of flight and to be derived from a different phylum, 

 the development of the pronotal picturing and cephalic marking 

 being distinctive. 



From the pronotal picturing, we believe it best to place the species 

 in linear arrangement after C. fossicauda Hebard, described from 

 Trinidad. 



The adult male probably shows distinctive genitalic features, 

 as is indicated by the immature examples of that sex at hand. 



Type: 9 ; Carcarafia, Santa Fe, Argentina. [Hebard Collection, 

 Type No. 681.] 



Size small, form moderately robust for the genus of very small and 

 moderately slender species. Head with interocular space very slight- 

 ly wider than that between antennal sockets. **i Ocellar spots poor- 

 ly defined. Pronotum with surface evenly and weakly convex, 

 greatest width near caudal margin, that margin transverse, show- 

 ing practically no convexity. Tegmina strongly reduced, over- 

 lapping but not reaching beyond median segment, costal margin 

 rounding very broadly into transverse distal margin, sutural margin 

 straight, rounding suddenly into distal margin a short distance 

 beyond the anal field, with longitudinal trend of discoidal sectors 

 discernible. Wings minute aborted pads, reaching to base of 

 median segment. Supra-anal plate triangularly produced with 

 immediate apex minutely emarginate, length one-third prox- 

 imal width. Subgenital plate scoop-shaped, projecting moderately 

 mesad, the lateral portions raised so that the plate appears broadly 

 V-shaped mesad when seen from the rear. Ventro-cephalic margin 

 of cephalic femora armed with a row of spines which decrease rapidly 

 and irregularly distad, terminated by two elongate spines; ventro- 

 caudal margin armed with two widely spaced spines meso-distad 

 and a single distal spine. Other ventral femoral margins moderately 

 suppUed with spines. Succeeding tarsal joints two-thirds as long 

 as caudal metatarsus, the four proximal tarsal joints supplied with 

 moderately well-developed pulvilli. Large arolia present between 

 the very feebly specialized, symmetrical tarsal claws, these claws 



*i This is slightly narrower than in lutea minima and appreciably narrov/er 

 than normally in the West Indian genotype, C. delicahila (Guerin). 



