362 HETEROPTEROUS HEMIPTERA. 



GERRIS Latr. 



1. G. REMiGis. — Dark olivaceous; thorax rounded behind, 

 without an elevated line. 



Inhabits United States. 



Body dark brownish-olivaceous ; thorax transversely rugulose 

 without much appearance of a dorsal raised line : a dull ochra- 

 ceous and indented line before ; posterior margin regularly and 

 obtusely rounded with but a very narrow depressed margin : 

 tergum with a black line on the middle, in which is a series of 

 obsolete gray lines ; lateral margin with a series of grayish points 

 or short transverse lines : beneath with a silvery sericeous reflec- 

 tion, an impressed line on the anterior part of the pectus behind 

 the anterior feet. 



Length half an inch. 



A great similarity exists between some of the species of this 

 genus, and I have ventured to separate this species from the 

 paludum F., which is said to have an elevated line on the thorax 

 and another on the pectus and postpectus. [807] 



The thorax on the posterior segment is generally obtusely 

 tinged with dull yellowish, with a blackish longitudinal line in 

 the middle. 



Var. a. Thoracic elevated line rather more obvious : grey lines 

 of the middle of the tergum more distinct. 



Inhabits Mexico. 



2. G. MARGINATUS. — Tliorax with an elevated line : behind 

 with an obvious depressed margin ; abdominal margin dull rufous. 



Inhabits United States. 



Body blackish, more or less tinged with olivaceous : thorax 

 with a raised line, more elevated behind ; lateral indented edge 

 dull rufous ; posterior depressed margin rather wide and very 

 obvious : abdomen with the margin dull rufous : feet dull rufous ; 

 anterior thighs with a blackish line on both sides ; coxae dull 

 rufous beneath : beneath with a slightly elevated line, termi- 

 nating anteriorly in a depressed one ; blackish, with a silvery 

 reflection. 



Length over seven-twentieths of an inch. 



