174 BULLETIN 182, UNITED STATES NATIONAL MUSEUM 



XXV. Genus OSORIUS Latreille 



Osoritis Latreille. 1829, p. 438. 

 Molosoma Say, 18'34, p. 4G2. 



Genotype. — Oxytelus latipes Gravenhorst=<9^<?Wws latipes (Gra- 

 veiihorst) (designated here). Of Molosoma^ same (monobasic). 



Diagnosis. — Body cylindrical, generally pubescent; clypeus not 

 separated from the vertex; labrum transverse; gular sutures united, 

 sometimes obsolete; mentum transverse; maxillary palpus filiform, 

 fourth segment elongate; antennae geniculate; prosternum with a 

 rounded or tuberculate prominence at middle anteriorly; anterior 

 coxal cavities separated by a narrow process of the prosternum which 

 is far below the coxae, narrowly open behind; anterior coxae large, 

 prominent, with a transverse sulcus on the outer face; middle coxal 

 cavities narrowly separated by the union of mesosternal and meta- 

 sternal processes; posterior coxae contiguous, "transverse," not much 

 expanded under the femora; abdomen not margined (entirely with- 

 out paratergites) ; first and second sternites absent; third sternite 

 carinate at middle; tibiae generally much enlarged, dentate, and 

 with many large spinules ; tarsi 5-segmented. 



Remarks. — Our species of Osorius have been studied twice within 

 the past 15 years, but our knowledge of the genus is still so slight that 

 I have prepared another complete revision. This genus is not readily 

 adaptable to presentation in a key, but I have drawn up as good a 

 one as I can at present, taking several characters from Darlington's 

 key. There are several complexes in which the species are very feebly 

 distinguished. These are usually represented by inadequate material, 

 so that the true status cannot yet be determined. 



I am adding four new species and correcting four previous misiden- 

 tifications. I have likewise included one species known only from 

 Trinidad and one known from Trinidad and South America. 



A specimen with abdomen missing stands in the British Museum 

 series of O. ater Perty from South America. It is labeled ".Jamaica" 

 and was received by the Museum in 1845 with the specimen mentioned 

 under 0. kuhhardi Notman. I believe it to be (9. ater but am very 

 doubtful of the locality. 



Osorius fav/veli Cameron (1913b, p. 326) belongs in the genus Mi- 

 mogonus and is a synonym of M. fumator (Fauvel) as stated by Cam- 

 eron (1923, p. 398; etc.) and by Scheerpeltz (1933, p. 1129). 



I have examined over 425 examples of this genus from the West 

 Indies and a large series of other American species. Of the former 

 27 were examined in the British Museum, 44 were in the United States 

 National Museum, 30 were borrowed from the Museum of Compara- 

 tive Zoology, and 363 were collected by me in 1935-37. 



