PAPERS ON SPIDERS 579 



cephalothorax and of the falces, in the length of the legs, and 

 in the structure of the copulatory organs. In support of this 

 opinion I propose for them the genus Agyneta, of which a 

 diagnosis is given below. 



Diagnoses of the Genera discussed above. 



Centromerus Dahl. 



Outer teeth of the fang-groove three, inner none. Maxillas 

 quadrate, apical margin gently convex, chitinous, black. 

 Labium very short and broad, narrowed below the reflexed 

 tip. Femur i. (at least) bearing a spine or spines. Paracym- 

 bium of male very large, more or less crescent-shaped, hollowed 

 within ; epigyne of female with transverse fovea, divided by a 

 median process. Front middle eyes very small, close together, 

 their laterals at least three times as large. 



British species : silvaticus Bl., expertus Cb., prudens Cb., 

 arcanus Cb., emptus Jackson, serratus Sim., similis Kulc, 

 } commodus Cb., } adeptus Cb. 



Sub-genus : Centromeria Strand. 



Differs from true Centromerus in having a double series 

 of spines under all the tibiae, and several spines on meta- 

 tarsus iv. Also all the dorsal spines of the tibiae are of the 

 same strength and character, not larger and stronger on 

 the posterior legs as in true CeJitromerus ; the falces 

 are not granulate, nor the copulatory organs so much 

 developed. 



British species : bicolor Bl., concinna Thor. 



Mengia F. Cb. 



Outer fang-teeth four, equidistant, the fourth least; inner 

 teeth three, rather longer than broad at the base, acute, 

 equidistant. Maxillae much longer than broad. Tibiae all 

 bearing spines on both sides and beneath. Metatarsi also 

 spined ; femora spineless. 



British species : scopigera Grube, warburtonii Cb. 



