ANISOLABIS. 81 



The sides of the sixth and seventh segments of the male are 

 convex, often produced into a sharp point, striate, rugulose or even 

 carinate ; this feature is present on a feebler scale in the female. 

 Last dorsal segment in the S ample, subrectaugular, but broader 

 than long, less broad than the preceding segments ; in the 2 similar, 

 but somewhat narrower. Penultimate ventral segment of cT ovate 

 or roundly triangular ; broader in the $ . Branches of forceps in 



Fig. 5. — Sternal plates of Anisolabis maritima, Bon. 



the S of two types : (1) contiguous or subcontiguous, stout, nearly 

 straight, tapering, or (2) remote, straight at first and strongly and 

 abruptly bent inwards, the right branch often more strongly than the 

 left. In the $ the branches are contiguous, straight, stout, tapering. 



Range. Cosmopolitan. 



After the removal of those forms now separated into Borellia- 

 and the sinking of a number of names as synonyms, there are still 

 about two dozen species left in this genus, occurring in all parts of 

 the world. Their discrimination is often difficult, and it is- 

 absolutely necessary to know the male before a species can be 

 characterized or satisfactorily determined. 



Some species seem to have a very restricted distribution, though 

 two, A. maritima and A. annulijjes, have become cosmopolitan. 



Immature specimens of various species of Psalis are often placed 

 under this genus in collections, and sometimes may have beea 

 described as species. 



Table of Sj^ecies. 



1. Posterior margin of metasternal lobe 

 romided ; size great ; (forceps subcon- 

 tiguous, straight ; legs and antennae 



unicolorous) colossea, Dohrn, p. 82. 



1.1. Posterior margin of metasternal lobe 

 truncate ; size medium or small. 

 2. Branches of forceps of c? remote at the 

 base, strongly curved. 

 3. Thorax with faint median line ; 

 forceps of (5 abruptly bowed, with 

 a rectangular internal projection 

 on the right branch ] maritviut, Bon., p. 83^ 



