110 BULLETIN 18 2, UNITED STATES NATIONAL MUSEUM 



Genotype. — Staphylinus inors'dans V\xy^\i\\ = Oxyteliis morsitans 

 (Paykull) =Platystethus morsitatis (Paykull) (designated by West- 

 wood, 1938). Of Pycfocraems, Staphylimis morsitans Paykull = Pyc- 

 toa'a-erus morsitans (Paykull) (original designation). 



Diagnosis. — Body moderately elongate and depressed; antennae 

 11-segmented, not geniculate, outer segments transverse ; without 

 ocelli; elypeus not separated by a suture from the front; labrum 

 transverse, emarginate; mentum and submentum transverse; maxil- 

 lary palpi subulate; gular sutures united in front, more or less ef- 

 faced; pronotum not longitudinally sulcate; anterior coxal cavities 

 confluent, entirely open behind ; trochantin exposed ; front coxae large 

 and prominent; middle coxae widely separated by a process of the 

 metasternum; elytra dehiscent, sutural apical angles broadly rounded; 

 posterior coxae contiguous, "transverse," not greatly expanded under 

 the femora; abdomen strongly margined; sternum of first segment 

 not sclerotized; anterior and middle tibiae strongly spinose exter- 

 nally in a single row ; tarsi 3-segmented. 



Reinarks. — This genus is distinguished from Oxytelus (in addition 

 to the rather unsatisfactory characters used in most keys) by the 

 separation of the mesothoracic coxal cavities by the metasternum 

 and by th^ dehiscent elytra. It is a world-wide genus, generally of 

 wide specific distribution. 



I have found only one species in the West Indies. 



1. PLATYSTETHUS SPICULUS Erichson 



Plafijstrthus spicnlm Erichson, 1840, p. 784.— Casey^ ISSCb, p. 262.— Sharp, 



1887, pp. 687, 800.— ViLLADA, 1901, p. 33.— Bebnhauer and Schubert, 1911, 



p. 124.— Scheerpeltz, 1933, p. 1109. 

 Platasfethus exigmis DuVal, 1857, p. 41, pi. 6, fig. 22. — Chevrolat and Fauvel, 



1863, p. 438. — Bernhauer and Schubert, 1911, p. 123. — Leng and Mutchi-eb, 



1914, p. 404. 



Description. — Piceous with pronotum and elytra sometimes 

 rufescent, shining. Head subquadrate; antennae shorter than head 

 and pronotum, outer segments feebly transverse; labrum three times 

 as wide as long, emarginate, with membranous processes; mandibles 

 moderately elongate, toothed; maxillary palpi rather long, subulate, 

 fourth segment as long as third; gular sutures united near center, 

 obsolete anteriorly or vaguely and unevenly impressed; with two 

 anteriorly converging sulci simulating widely separated gular sutures. 

 Pronotum two-fifths wider than long; semicircular; midline feebly 

 impressed; very finely and very sparsely punctate; no ground 

 sculpture. Elytra dehiscent, inner apical angles broadly rounded, 

 outer ones narrowly rounded; moderately finely and sparsely punc- 

 tate, surface finely rugulose, especially apically. Abdomen impunc- 

 tate except at' edges of segments. Male., head with three longitudinal 



