52 Proceedings of the Royal Irish Academy. 



ov less cylindrical, with dermo-skeleton less solid than in PanctenodactyM, 

 polished, largely free from heavy sculptiu-e ; biistles simple.) 



1. Legs I. with tarsi 2-jointed Ohisiidae. 



2. Legs I. with tai-si l-jotnted Chthoniidae. 



OBISIIDAE. 

 All legs with tarei 2-jointed : femiu- of legs I. with longer pars basalis 

 and shorter pare tibialis ; legs IV. with artiexilation between trochantin and 

 femur alike on anterior and posterior faces. Cephalothoiux with anterior 

 median process ; not serrated Eyes 4, 2 or 0. 



Obisium. 

 OUsiiim (Dliger) Leach 1815 (12).' 



Cephalothorax broad in fi'ont, not broader in fi-ont than behind. Palps 

 with fingei-s always more or less curved, hand without doi^sal tactile haii's or 

 with one or several, tibia never cahciform. Galea present or absent. Eyes 

 4, 2, or 0. 



(Britaimic species with eyes 4 or 2, never with dorsal tactile haii's on hand. 

 All intensely glossy, with bristles long slender and imequal; gi-amilatiou 

 may occur on palps, but not on cephalothorax or abdomen ; abdomen 

 with lateral membrane sharply papillate : fused tergite-stemite of somite 

 XI. with perforation for somite XII. terminal or sub- ventral, weU-removed 

 from anterior ventral margin; somite XII. with separate tergite and 

 stemite each with 2 bristles ; cheheei'ae moderately lai-ge ; hand of palps 

 with abruptly limited stalk ; teeth of both fingei-s in close-set row, of movable 

 finger for most part tnmcate or broadly roimd?d offj of fixed finger generally 

 acute ; femora of legs III. and lY. deep or modemtcly deep ; in. legs III. 

 posterior face of femur, at least in 4-eyed species, with low papillation; 

 coxae I. with outer anterior comer prolonged into a point and with a more 

 or less obsolete point of different character at inner anterior comer ; 3 with 

 genital-area inconspicuous ; compared with 2 generally with hand less 

 voluminous, fingers a httle longer in proportion to hand, and sometimes with 

 tibia a little longer-stalked and narrower.) 



1. Cheheei'ae with galea ..... Ideoroncus. 



Chelicerae without galea 



2. Eyes 2 . . . 



3. Eyes 4 . . . 



2 



Roncus. 

 Obisium a.s? 



' Ohuiutn llliger (6) was a synonym of Chelifer; but was adopted by Leach (12) for the 

 present genus ; = Opwium misprinted (10). 



- Sub-gen. IdtohUium vrith galea and -J eyes is unrepresented in our fauna : as also are the 

 eyeless sub-gen. Blothrus and IdeoUothru$. 



