OPISTIIOCOSMIIJf.E. 175 



Subfamily IV. OPISTHOCOSMIIN^. 



This subfamily was originally erected by Verboeff and included 

 only two genera — Opisthocosmia and Cosmiella ; it was recast 

 iu 1907 by the author, but was too much split up and the genera 

 too scattered. The last dorsal segment of the male is narrowed in 

 the majority of cases ; but it so happens that in the type of 

 Opisthocosmia it is transverse, and consequently this is not a true 

 character of the group. Nor can the length of the leg be 

 sufficient, as in some forms undoubtedly related these are quite 

 short. The relative length of the third and fourth segment of the 

 antennae is not sufficiently constant to be of more than specific or 

 generic value. 



It is therefore accordingly now proposed to include in the 

 subfamily those earwigs in which the abdomen is scarcely or not 

 at all depressed, so that the surface is convex and a cross-section 

 circular. It will therefore absorb the subfamilies EparcJiince, 

 Neolohophonnce, Sl-endijUnce, and Eudohrnince, regarded as of sub- 

 family rank by the author in 1907. Under this new arrangement 

 the subfamily contains about sixteen genera, represented in all 

 parts of the world. There are two well-marked groups, charac- 

 terized by the presence or absence of a distinct keel down the 

 costal fold of the elytra. 



The carinate genera are five in number, of which three are 

 American and the rest Oriental, two being represented iu India. 

 Of the non-carinate genera, those with narrow pronotuiu are 

 represented in India by Cordax, as true Opisthocosmia is so far 

 only known in the Malay Archipelago. 



The forms with broad pronotura fall into two groups, according 

 to the length of the first tarsal segment : of the long-legged 

 genera one is American, the other three are represented in 

 India ; of those with short tarsi, apart from the three Indian 

 genera, there is one in America (Sarcinatrlc) and one in Java 

 {Rhadamanthus). Eudohrnia is well characterized by the tri- 

 carinate basal segment of the antennae. 



A peculiar group consists of Cordax ceijlonicus, Ohelura (two 

 species), Si/ntomis (one species), and Sonda.v (one species), all of 

 which have a strong superficial resemblance, although they are 

 rather widely separated by the structure of the elytra, pronotum, 

 tarsi, and last dorsal segment. They are discussed iu the 

 observations on Sondax repens (p. 177). 



