MONOGRAPH OF WEST INDIAN STAPHYLINIDAE 277 



XXXVII. Genus ORUS Casey 



Orus Caset, 1884, p. 136. 



Subgenus Leucorus Casey, 1905, pp. 191, 192, 



Subgenus Pycnorus Casey, 1905, p. 194. 



Genotypes. — 6>/'t^ punctatus Casey (designated by Blackwelder, 

 1939). Of Leucoru^^ L. imbens Casey (designated by Blackwelder, 

 1939) ; of Pycnorus^ Scopaeus dentiger IjeConte^ Pycnorus dentiger 

 (LeConte) (designated by Blackwelder, 1939). 



Diagnosis. — Body slender, strongly constricted; punctures of head 

 not umbilicate; eyes normal; antennae posteriorly flexile, strongly 

 geniculate, basal segment not very elongate, first and second segments 

 not larger than rest ; labrum not very deeply emarginate ; fourth seg- 

 ment of maxillary palpus subulate; gular sutures moderately separate, 

 not strongly converging at either end; neck more than one-fourth as 

 wide as head ; pronotum distinctly longer than wide ; prosternum not 

 expanded under coxae laterally; hypomera feebly lobed behind the 

 coxae; anterior coxal cavities open behind; front coxae large, exserted; 

 middle coxal cavities confluent ; posterior coxae contiguous, "conical" ; 

 first and second abdominal sternites absent, fourth and fifth sometimes 

 with a transverse fold, seventh modified, eighth emarginate ; basal half 

 of front tibia with a concavity lined with diagonal ctenidia ; apex of 

 posterior tibia with a ctenidium only on inner edge. 



Remarks. — This genus is very similar to Scopaeus, from which it is 

 distinguished principally by the width of the neck. The wide separa- 

 tion of these two genera in the key (see Blackwelder, 1939) is mis- 

 leading and is corrected in the generic arrangement. 



I have examined 51 specimens of this genus and describe two new 

 species to receive them. The Scopaeus umbra oi Sharp is distinct 

 from either of these and is not known to me from the West Indies. 



KEY TO WEST INDIAN SPECIES OF ORUS 



1. Elytra with distinct punctures, without ground sculpture 1. volans 



Elytra without distinct punctures, with dense ground sculpture- 2. cameroni 



1. ORUS VOLANS, new species 



Description. — Testaceous. Head distinctly emarginate behind, the 

 angles rounded ; the eyes separated from base by more than three times 

 their length; labrum bidenticulate, with a minute prominence at 

 each side; gular sutures moderately separate, almost parallel; without 

 distinct punctation but with dense but feeble ground sculpture. Pro- 

 notum one-fourth longer than wide, angles rounded, sides not at all 

 emarginate in front ; midline slightly elevated posteriorly ; with rather 

 distinct punctures but obscured by fine ground sculpture. Elytra 

 somewhat coriaceous but with distinct and rather large punctures; 

 without distinct ground sculpture. Male unknown. Female., eighth 



