322 BULLETIN 182, UNITED STATES NATIONAL MUSEUM 



verse ; gular sutures converging toward line of constriction from both 

 ends ; prosternum short, not carinate, abbreviated between and under 

 coxae forming an acute point w^hich does not attain the mesosternum ; 

 anterior coxal cavities narrowly open behind ; front coxae very large, 

 conical, prominent; middle coxal cavities confluent; posterior coxae 

 large, conical, contiguous; abdomen margined; first and second ster- 

 nites absent; eighth sternite excised in male, lobed in female; tarsi 

 6-segmented, fourth segment bilobed. 



Remarks. — I have made no changes in this genus except in the char- 

 acters used to distinguish it and its parts. It is one of the most easily 

 recognized of the Staphylinidae. 



Fifty-four examples from the West Indies are herein assigned to 

 four species, of which one is new. 



KEY TO WEST INDIAN SPECIES OF PAEDERUS 



1. Color uniform rufotostaceous throughout 3. jamaiceusis 



Color in part blue or black 2 



2. Body black throughout 4. morio 



Body in part rufous or testaceous 3 



3. Abdomen entirely black 2. homonymus 



Base of abdomen testaceous 1. mutans 



1. PAEDERUS MUTANS Sharp 



Paederus mutant Sharp, 1876, p. 286. — Beknhauer and Schubert, 1912, p. 209. — 

 PLA\^LSTSCHIKov, 1929, p. 29. — Blackwei>der, 1939a, p. 112. 



Description. — Rufotestaceous, elytra cyanescent, seventh and eighth 

 abdominal segments black. Head with eyes a little wider than long, 

 with moderate but very shallow punctures separated by one to three 

 times their width, each puncture with a long black hair; labrum with 

 a small triangular notch at middle, rather truncate in front with mar- 

 gin indistinctly crenulate. Pronotum, one-sixtli longer than wide, wid- 

 est at anterior fourth, distinctly narrowed behind ; punctures finer and 

 sparser than on head but with similar hairs. Elytra as wide as pro- 

 notum, over one-sixth longer than wide ; punctures coarse and deep, 

 separated by less than their diameter by feebly convex intervals; su- 

 ture feebly raised throughout. Abdomen with sparse and fine punc- 

 tures more or less transversely serial, each wath a long black hair, 

 submuricate especially on apical segments ; with feeble ground sculp- 

 ture. Male^ eighth sternite with "the usual excision." Female., eighth 

 sternite deeply semicircularly emarginate on each side at apex, leaving 

 prominent angles and an acuminate triangular median lobe. Length, 

 8 to 9 mm. 



Type locality. — "Tapajos and Para," Amazon Valley, (Brazil). 



Types. — In the British Museum. 



