396 PROCEEDINGS OF THE NATIONAL MUSEUM vol.84 



Antennae 0.5 mm long, reaching metastemum; segments 3 and 4 

 equal; 5-10 each slightly broader but no longer than 4; 11 rounded, 

 almost twice as long as 10. Apical segment of maxillary palpi enlarged, 

 form of an elongate scalene triangle, sides straight, corners rounded. 

 Pronotum slightly broader than long (0.5 by 0.45 mm), convex, sides 

 finely margined, basal angles obtuse, midbasal lobe distinct, broadly 

 rounded. Scutellum small, triangular, broader than long. Elytra 

 twice as long as broad (1.2 by 0.6 mm), sides gently curved, apices 

 individually rounded. Posterior tibiae with two oblique ridges, the 

 basal extending entirely across outer face; basitarsi with two oblique 

 ridges, second segment with one oblique ridge, all extending halfway 

 across outer surface. Anal style more than two and one-half times as 

 long as apical ventral segment, slender, truncate at apex. 



The female has the pronotum entirely black. The scutellar area of 

 the elytra is more extensive than in the male, reaching the lateral 

 margins, and the black sutural line is somewhat broader. 



Type locality. — Ponce, Puerto Rico. 



Type.— Male, U.S.N.M. no. 51602. 



Remarks. — The type and allotype were taken at Ponce on April 29, 

 1933, on leaf of "moca" by R. G. Oakley; a female paratype was taken 

 at Juana Diaz on February 23, 1933, on coffee leaf by R. G. Oakley. 

 Here occurs one of the most striking cases of sexual dimorphism noted 

 in the Mordellidae, the difference in color at once enabling an observer 

 to separate the sexes. 



This species is dedicated to H. S. Barber, for his kindness in arrang- 

 ing for the transmittal of specimens described herein and for other 

 favors. The pin label of the type in Mr. Barber's handwriting 

 indicates its undescribed condition. 



MORDELLISTENA LEAI, new species 



Figure 28, h, j 



The expanded condition of the anterior tibiae in this species ade- 

 quately separates it from any other known member of the genus. 

 Superficially it resembles signaticollis Quedenfeldt (1886, p. 125) and 

 marginicollis Maklin (1875, p. 590). 



Length: 2.4 mm; including anal style, 3.6 mm. Elongate, sub- 

 parallel; derm black, except for the following flavous areas: Anterior 

 part of head from a point beginning midway between eyes, and a 

 narrow transverse line at base, sides of pronotum (broadest at anterior 

 angles), a humeral spot on elytra extendmg one-tliird entire length 

 and toucliing neither suture nor margins; antennae with four basal 

 segments flavous, remainder fuscous, maxillary palpi and legs flavous 

 (except hind femora). Surface densely covered with fine, short, 

 recumbent pubescence, generally yellowish in color. 



