438 ARACHNIDA CHERNETIDEA chap, xvi 



running 1)ackwards or sideways with their pedipalpi closely 

 folded up against the body. Four genera usually admitted fall 

 within this group : — Obisium, Roncus, Blothrus, and Chthonius. 



Ohisium has four eyes, parallel - sided cephalothorax, and 

 curved chelae on the palps. Roncus is like Ohisnim except in 

 having only two eyes, and is therefore disallowed by Simon, who 

 also considers Blothrus to comprise merely eyeless species of 

 Ohisiiun. In Chtho7iius the cephalothorax is broadest in front, 

 and the digits of the chelae are straight. 



The Obisiinae are found in moss and debris, and under stones. 

 Three species of Ohisium, two of Boncus, and four of Chthonius 

 are recorded in England. 



The subjoined list of British species of Chernetidea is taken 

 from the monograph of the Eev. 0. P. Cambridge, cited above : — 



Group I. — Four eyes. 



Chtlwnius oiihodactylus. Leach. 

 „ rayi, L. Kocli. 

 ,, tetrachelatus, Preyssler. 

 „ tenuis, L. Kocli. 

 Ohisium inuscorum, Leacli. 



„ sylvaticuw, C. L. Kocli. 

 „ maritimum. Leach. 



Group IL — Two eyes. 



Roncus camhridyii, L. Kocli. 



„ JuhricHs, L. Koch. 

 Chelifer hermannii, Leach. 



„ cancroides, Linn. 



„ meridianus, L. Koch. 



„ subruber, Simon. 



„ latreiUii, Leach. 



Group IIL — No eyes. 



Chernes nodosiis, Schr. 



„ insuetus, Camb. 



„ cimiroides, Fahi'. 



„ dubius, Camb. 



„ phaleratus, Simon. 

 Chiridium viuseorum, Leach. 



