MONOGRAPH OF WEST INDIAN STAPHYLINIDAE 203 



Diagnosis. — Body in part subcylindrical, glabrous; eyes very large 

 and prominent, antennae 11-segmented, clavate; elypens feebly sepa- 

 rated from vertex, anterior angles toothed; labrum visible only as 

 two slender processes; maxillary palpus filiform, first segment short; 

 mentum oblong ; gular sutures strongly converging at base but anterior 

 to pits are more widely separate and parallel; prothorax subcylindri- 

 cal ; pronotum transversely sulcate ; prosternum with a transverse row 

 of punctures in front of the coxae ; anterior coxal cavities separated by 

 a slender process of the prosternum, half open behind ; anterior coxae 

 very small but prominent, without sulcus on anterior face; meso- 

 sternum carinate ; middle coxal cavities separated by union of meso- 

 sternal and metasternal processes; posterior coxae contiguous, small, 

 transverse, not expanded under femora ; abdomen margined ; first and 

 second sternite absent ; third sternite carinate at middle basally ; sexes 

 not greatly differing ; tibiae unarmed, tarsi 5-segmented. 



Remarks. — This is a very distinct genus in regard to a great many 

 characters. I know of no important summary or study of its struc- 

 ture, but the following can be mentioned as being of unusual structure 

 or development: The bicornute labrum, the toothed clypeus, the cla- 

 vate antennae, the gular sutures, the prosternum and coxal cavities, 

 the mesosternal and metasternal processes, and the fourth tarsomere. 



This genus was described by Erichson under the name Megalops 

 and was known by that name for 90 years. In 1918 Leng found it 

 to be preoccupied and renamed it Megalopsidia. In 1921 Benick came 

 to the same conclusion and offered the new name Aulacotrachelus, in 

 apparent ignorance of Leng's proposal. The genus now stands in all 

 recent works as Megalopsidia Leng. However, in 1917 Benick pro- 

 posed simultaneously two new subgenera, Stylopodus and Perostylus. 

 Nomenclaturally, these must be considered as available names with 

 priority over Megalopsidia and all later names. It is therefore 

 necessaiy to choose one of these two for the name of the genus and 

 leave the other (with Megalopsidia and the still later Megalopisidi- 

 ella) as subgenera. Inasmuch as Perostylus is itself a homonym, 

 Stylopodus is the first available name and must be accepted for this 

 genus. The only name that escapes unchanged from this reorgani- 

 zation is that of the subgenus Megalopsidiella. 



I know of 6 species from the West Indies and have examined 36 

 examples from the islands beside a considerable series from South 

 and Central America. 



KEY TO WEST INDIAN SPECIES OF STYLOPODUS 



1. Elytra entirely impunctate 2 



Elytra with some punctures 3 



2. Elytra with large testaceous discal area 1. smithi 



Elytra unicolorous, piceocastaneous 2. impressus 



