174 bulletin: museum of comparative zoology. 



Otostigmus suitus, sp. nov. 



Color olive-green with some of the dorsal plates appearing darker 

 along the caudal margin. Antennae more brownish excepting at 

 base. 



Head distinctly punctate. Marked in front of caudal margin with 

 two short longitudinal furrows. 



Antennae seventeen jointed.^ First two or two and a half articles 

 glabrous (the third in type partially rubbed so that precise extent of 

 glabrous condition is uncertain); other articles clothed densely with 

 the usual short brown hairs. 



Dorsal plates from the fourth, inclusive, caudad with two distinct 

 median sulci; a longitudinal depression or furrow on each side, but 

 true margination present only on the twenty-first plate, plates mostly 

 depressed between median sulci and wdth a weakly developed median 

 keel indicated on plates from the third caudad; the surface and edges 

 of plates wholly smooth. Last dorsal plate with posterior margin 

 bowed moderately caudad. A median pit-like depression in front of 

 caudal margin and a keel in front of this as on the other plates. 

 (Plate 3, fig. 4). 



Prosternum with 4+4 teeth of which the second from the mesal 

 incision on each side is the largest, the third being next. 



Ventral plates without a trace of longitudinal sulci. Each with three 

 distinct, pit-like, or more or less longitudinal, impressions arranged 

 in a triangle with the apex cephalad, and with three short longitudinal 

 impressions in a transverse row in front of the caudal margin. Last 

 ventral plate strongly narrowed caudad. Truncate caudad with the 

 corners a little rounded. Impressed with a distinct median longi- 

 tudinal furrow. (Plate 3, fig. 3). 



Coxopleurae of last legs without any true process, being a little 

 roundly extended caudad; without any spines. 



Length cir. 55 mm. 



Locality. — State of Matto Grosso : Madeira-Mamore R. R. camp 

 41, on the Rio Madeira! (W. M. Mann). 



One specimen was secured. 



1 On one side of type specimen there are but thirteen articles in the antenna, this 

 being due, apparently, to breaking off of the antenna with subsequent regeneration 

 of the distal article. 



