54 Proceedings of the Royal Irish Academy. 



III. Obisium s.s. 



Chelicerae without galea ; eyes 4. 



(Britannic species 3 : dorsum of eephalothorax, abdominal tergites, femur 

 and tibia of palps smootli ; hand in part smooth in part obsolete-granulate. 

 Eyes well-developed, near together and somewhat tilted on common raised 

 base ; between them and partly round the first a blaekisli patch ; chelicerae 

 with tubercle of movable finger well-developed, differing according to 

 species, and generally larger in ? than in <? ; femur of palps with scarcely 

 differentiated stalk.) 



1. Cephalothorax with median process obsolete . mvscorum. 

 Cephalothorax with median process prominent ... 2 



2. Fingers longer than hand ..... Carpenteri. 



3. Fingers scarcely as long as hand . . . inaritiinum} 



0. muscorum Leach. 



0. muscorum Leach 1817 (13). 0. simUe (L. Koch) Simon 1879 (27) ; in 

 part.^ 



Palps clear reddish-horny, eephalothorax and abdommal tergites deep 

 olive, the former with reddish tinge, legs horny. Cephalothorax with 

 median j)i'ocess obsolete ; chelicerae with tubercle of movable finger ( j ) 

 high almost semi-circular, teeth of fixed finger small ; palps (fig. 16) with 

 femur almost equally liroad near base and near extremity, towards middle 

 distiuctly concave Ijehind with corresponding convexity in front, tibia 

 scarcely or not broader than femur, membranous opening about g front 

 margm (stalk excluded), liand variable more or less tumid and of only 

 moderate length (in $ more ^■ohnninous than in 3' ), fingers much longer than 

 hand, teeth of fixed finger slightly tapermg and rounded at tip with broader 

 higher sharply pointed ones at intervals, teeth of movable finger distinct ; legs 

 IV. with tarsus' much longer than tarsus' (at least 1'3). L. 2'8. 



Under stones, among dead leaves, moss, etc., in the open and in \\'oods, from sea-level to 3,500 

 it. ; generally distributed and abundant in Britain and Ireland. 

 (13, 42, 44, 51, 58, 65, 70-1, 75, 79, 85, 87, 91-2, 94.) 



' 0. sylvaticnm C. L. Koch has by mistake been recorded as British (42) ; the specimen, dis- 

 figiu'ed in preparation for the microscope, "was in reality 0. hihricum. Eecords of 0. simile L. Koch 

 in Britain (30, 36) aie also erroneous ; they relate to 0. muscorum. 



■ That the present species is 0. iimscornin Leach is sure from the type which is preserved in the 

 British Museum, where it has been examined by Cambridge (42) and by the writer (94). Simon 

 confused this animal with 0. simile L. Koch ; and has unfortunately applied Leach's name to another 

 species, i.e. 0. Carpenteri. In spite of tliis fact, however, the 0. muscorum Leach of most writers 

 appears to be correctly named; and this is certainly the case with Hansen (34), Tullgren (46), 

 With (66), and Ellingsen (75). The writer is indebted to M. Simon for specimens from liis collection 

 of " 0. simile" (0. simile L. Koch and 0. muscorum Leach) and " 0. muscorum " {0. Carpenteri). 



