88 NEOTROPICAL P3ELAPHIDAE 



sulcus ; lateral mesocoxal foveae obvious ; metasternal foveae fused and median. 

 Posterior coxae shortly conical, subcontiguous. 



Anterior femora and tibiae inflated ; anterior tibiae basally sinuate, with a 

 minutely serrated carina along the ventro-anterior face in basal half. 



Tarsi three-segmented; first tarsomere small, second and third much larger; 

 second longest and much thicker than third, this thickness being due to the 

 dorso-ventral width, the segment being laterally compressed; third slightly 

 arcuate and thick; tarsal claws primitive, very unequal, with a large, thick, 

 arcuate, pointed primary claw and a very thin secondary claw which is half 

 as long as the first. 



Described on a single female specimen, from Matto Grosso, near Corumba, 

 in Brazil. I dedicate this striking species to a lamented friend of long standing, 

 Mr. H. C. Fall.^ 



Rhinos cepsis dybasi new species 



Type Male: Measurements: head 0.27 x 0.23 mm.; pronotum 0.25 x 0.28 

 mm.; elytra 0.30 x 0.40 mm.; abdomen 0.50 x 0.40; antennae 0.43 mm. long; 

 total length 1.3 mm.; greatest width 0.4 mm. 



Yellowish brown, subopaque with flavous, abundant, short pubescence; the 

 distal segment of maxillary palpi swollen and light yellow. 



Head with prominent, rounded tempora which are slightly convergent an- 

 teriorly, three times longer than the eyes, and slightly longer than wide; eyes 

 hardly visible from above, rudimentary, composed of 8 facets lying within the 

 cephalic sulcus. Apical end of rostrum transversely ovate. Cephalic sulcus hold- 

 ing the eye and the ovate genal fossa relatively larger, being more than twice 

 as large as eye. Head otherwise as in falli. 



Maxillary palpi four-segmented, as in falli save for distal segment. This 

 latter segment tumid, yellow, ovate with rounded base and subacute apex, ven- 

 tral face flattened; veiy large for the genus, being slightly more than three times 

 as wide as third, and nearly four times as long. (In the male bistriatus of the 

 United States the fourth segment is about twice as wide as third, and in falli 

 the fourth is twice as wide as third.) 



Antennae long, slightly more than one third the body length, eleven-seg- 

 mented ; segment I subconical with the ventral face strongly produced at base, 

 twice as long as second (this is very distinctive when contrasted with the cyl- 

 indrical flrst antennomere of males of bistriatus and falli); II ovate; III-VI 

 moniliform; VII-VIII transversely moniliform, longer and wider than eighth; 

 X transverse, drum-shaped ; XI ovate-acuminate. 



'I owe much to Mr. Fall, who encouraged my work on Pselaphidae through examina- 

 tion of specimens and long, instructive letters. My earliest taxonomic attempt was on two 

 different families of Coleoptera, including a new genus of Cryptophagidae {Glyptophonis 

 mycetoecus Park, 1929). Mr. Fall subsequently examined the types, pronounced the species 

 valid, and found an undescribed specimen in his own collection which belonged to mycetoe- 

 cits. Such aid to a young taxonomist, and long correspondence concerning Rybaxis and other 

 pselaphids, were very stimulating, and I take this opportunity to express my gratitude. 



