GEOCORIS-E. INSECTS. 319 



FAMILY I. GEOCORIS.E. 



Antennae longer than the head, inserted near the internal mar- 

 gin of the eyes ; tarsi with three joints, the first sometimes 

 very short. 



The insects of this family are for the most part terrestrial ; those which frequent 

 the water being found only on its surface or margin. 



TRIBE I. LONGILABRA. 



Sheath of the sucker with four distinct joints ; labruin long, 

 subulate, and striated above. 



I. Two ocelli ; antennas always filiform, or thickest at the end. 



1. Antenna? of five joints. 



Gen. SCUTELLERA, CANOPUS, JELIA, CYDNUS, EDESSA, PENTATOMA, 

 HALYS, HETEROSCELES. 



2. Antennae with three joints. 



Gen. PHLJEA. 



3. Antenna with four joints. 



A. Head dilated and rounded like a hood, the sides covering the base of the antenna?. 



Gen, TESSARATOMA, (Edessa papillosa, Fab.) 



B. Head not dilated like a hood ; insertion of the antennae uncovered. 



a. Antennae inserted on the lateral and upper margin of the head, above an ideal 

 line drawn from the eyes to the origin of the labrum ; two distinct ocelli in all. 



Nerves of the membranous appendage of the elytra very distinct and numerous ; 

 posterior thighs of the males often tumid. 



* Interval between the two ocelli almost equal to that between the eyes. 

 | Head, seen above, square or triangular. 



Last joint of the antenna ovoid, shorter than the preceding, tumid or compressed. 



Gen. GONOCERUS, (the two last joints of the antenna flat) ; SYROMASTus(the 

 third joint longer than the preceding, and the last ovoid) ; COREUS (the third 

 joint filiform, the length of the preceding or shorter, the last oval or fusiform. 

 This genus is divided into two sections, as they have the head square or tri- 

 angular. 



Last joint of the antenna cylindrical, the thickness of the preceding, or more 

 slender and as long. 



Gen. HOLHYMENIA, (second and third joints of the antenna flattened) ; PACH- 

 LYS (the third joint flattened) ; AN ISOSCELES, (antennae of medium thick- 

 ness, short) ; NEMATOPUS (antenna very slender, the length of the body.) 



"J"-|- Head narrow, cylindrical, projecting, and narrowed into a point posteriorly. 



Gen. STENOCEPHALUS. 



The first two joints of the antenna longest : the first thickest. 

 ** Ocelli approximated. 

 { Antenna straight or not geniculate. 



Gen. ALYDUS, LEPTOCORISUS. 

 }"{ Antenna geniculate. 



Gen. NEIDES. 



b. Antenna inserted on the inferior sides of the head, either on an ideal line drawn 

 from the eyes to the origin of the labrum, or below it. 



Membranous appendages of the elytra with small cells at their base, or having only 

 four or five nerves. 



