MONOGRAPH OF WEST INDIAN STAPHYLINIDAE 209 



Subgenus Hyposteniis Rey, 1883, p. 183. 



Astcnns Lynch, 1884, p. 341. 



Steuosidotus Lynch, 1884, p. 338. 



Areus Casey, 1884, p. 150. 

 Subgenus Tcsnus Rey, 1883, p. 183. 



Mutinus Casey, 18&4, p. 146. 



Genotypes. — Stenibs 2-guttatus Fabricius (designated by Latreille, 

 1810). Of Nestms., Stenus {Nestus) 'boops Ljungb (designated by 

 Tottenham, 1940) ; of Hyposten<us^ Sienus {Hypostenus) hiesenwetteri 

 Rosenhauer (designated by Tottenham, 1940) ; of Astenits, Stenus 

 (Astenu^) specidifrons Fauvel (monobasic) ; of Steuosidotus, Stenus 

 i^Stenosidotus) aenescens Lynch (monobasic) ; of Hemistenus, Stenus 

 (Hemistenus) paUitarsis Stephens (designated by Tottenham, 1939) ; 

 of Areus, Stenus flavicomis Erichson = Areus flavicornls (Erich- 

 son) (designated here) ; of Mesostenus, Stenus (Mesostenus) im- 

 pressus Germar (designated by Tottenham, 1939) ; of ParastenuSj 

 Stenus {Parastenus) impressus Germar (by synonymy with Meso- 

 stenus) ; of Tesnus, Stenus (Tesnus) opticus Gravenhorst (designated 

 by Tottenham, 1940) ; of Mutinus, Stenus {Mutinus) dispar Casey 

 (designated here) . 



Diagnosis. — Body elongate, cylindrical ; labrum transverse, rounded 

 in front; antennae 11-segmented, elongate and slender, more or less 

 clubbed; first segment of maxillary palpus elongate, third large, 

 fourth minute; last segment of labial palpus normal; mentum sub- 

 quadrate, strongly carinate at middle; gula broad, sutures conver- 

 gent at middle; anterior coxal cavities confluent, open behind; an- 

 terior coxae small but conical and rather prominent; middle coxal 

 cavities narrowly separated by union of mesosternal and metasternal 

 processes; posterior coxae "conical," not expanded laterally because 

 of the proximity of the pleurites; first and second abdominal sternites 

 not sclerotized ; third carinate ; males with apical segments modified ; 

 tarsi 5-segmented. 



Remarks. — This very large and widespread genus is readily recog- 

 nizable by its appearance. The large eyes and the insertion of the 

 antennae into the upper surface of the head near the eyes will dis- 

 tinguish it from all other staphylinids. The genus has been divided 

 into several subgenera, but there is no complete agreement as yet 

 on the characters to be used for this purpose. 



I have examined 113 West Indian examples belonging to 20 species 

 of which 15 appear to be new. These belong to at least three of the 

 subgeneric groups listed above. 



KEY TO WEST INDIAN SPECIES OF STENUS 



1. Abdomen strongly margined 2 



Abdomen not distinctly margined 4 



