328 PROCEEDmCS of the national museum vol.09 



opaque along base, and sparsely, irregularly clothed with short, in- 

 conspicuous hairs. Scutellum smooth, round, or oblong. 



Elytra slightly wider than pronotum at base; humeral angles ob- 

 tusely angulated or broadly rounded ; sides nearly parallel from bases 

 to apical thirds, then arcuately converging to the tips, which are con- 

 jointly broadly rounded, the margins coarsely serrate near apices. 

 Each elytron with four or five more or less distinct longitudinal cos- 

 tae; presutural costa when present, extending from base to basal 

 fourth ; two distinct median costae extending from base to apex, and 

 expanded toward base; two more or less distinct prelateral costae, 

 the inner one distinct at middle, interrupted anteriorly and posteriorly, 

 the outer one only distinctly elevated toward apex; with 10 rows of 

 coarse, deep, distinctly separated punctures arranged in double rows 

 between the costae; intervals between costae more or less rugose 

 basally, finely, sparsely, irregularly punctate, and with a few short 

 inconspicuous hairs. 



Abdomen beneath finely, densely punctate, confluently toward sides, 

 rather densely clothed with short, recumbent, whitish hairs ; intervals 

 smooth and shining ; first sternite slightly flattened and vaguely punc- 

 tate at middle; last visible sternite broadly rounded at apex. Pro- 

 sternum strongly convex ; slightly gibbose on each side along anterior 

 margin, coarsely, deeply punctate, the punctures coarser and confluent 

 toward sides, rather densely clothed with moderately long, recumbent, 

 whitish hairs; anterior margin slightly elevated, feebly, broadly 

 emarginate; prosternal process smooth, sparsely, finely punctate, 

 without marginal grooves, sides obliquely converging to apex, which 

 is narrowly rounded. 



Male. — Differs from the female in being smaller, in having the first 

 abdominal sternite finely, densely punctured, and the last visible 

 abdominal sternite narrowly rounded at the apex. 



Length 11-25 mm., width 4.5-9.75 mm. 



Type locality, — Guayaquil, Ecuador. 



Type^ allotype^ and paratypes. — U. S. N. M. No. 58782. 



Described from 48 specimens (1 type). The type, allotype, and 42 

 paratypes were collected at the type locality by F. Campos E, ; three 

 paratypes were collected at the same locality during 1915 by W. F. 

 Goding; and one paratype was collected in the vicinity of Piurat, 

 Peru, during February 1940, by J. Soukup. 



This species is very closely allied to Polycesta velasco Castelnau and 

 Gory, but it differs from the description given for that species (de- 

 scribed from Mexico) in having the sides of the pronotum angulated 

 behind the middle and the surface rather deeply depressed at the 

 middle, the elytron with only two longitudinal costae extending from 

 the base to the apex, and the first abdominal sternite of the male 

 without a densely pubescent spot at the middle. 



