50 NEW AND RARE BRITISH SPIDERS 



the past summer I submitted British examples to him for 

 comparison with his type specimen. Having compared 

 the two, he says that they are identical save for a slight 

 difference in the copulatory organs, such as frequently 

 appears in spiders of the same species widely separated 

 geographically. He is therefore inclined to regard evansii 

 Cb. as a sub-species of aliena Kulcz., and perhaps that is 

 the simplest method of recognizing both the agreement 

 and the difference. The difference in this case is solely 

 in the position of a minute spine on the middle coil of the 

 central spiral vessel of the copulatory apparatus of the 

 male. It is on the anterior face in British examples, on 

 the posterior in the Kamschatkan type (pi. ii., figs. 

 14, 15). It may be observed that this genus also has 

 affinities with the Oedothorax group, but in a systematic 

 arrangement it ought probably to stand nearer to 

 Dicymbium and Tiso. 



Troxochrus scabriculus Westr. Mr. F. P. Smith suggested 

 to me some time ago that a new genus was required for 

 this species. That, as it happens, is impossible; for 

 Simon makes it the typus of Troxochrus. Nevertheless it 

 is true that it ought not to be considered congeneric with 

 hiemalis Bl. and ignobilis Cb. On "the other hand it 

 appears to me to agree in all essential generic characters 

 with Tapinocyba, differing in nothing but what is incidental 

 to its somewhat larger size. In fact the agreement is so 

 absolute that I see no valid reason for maintaining two 

 separate genera for these spiders. An appeal to the 

 dentition of the fang-groove confirms this view. In the 

 alliance to which these spiders belong, the number of 

 inner teeth may be 3, 4 or 5, and the number 4 occurs 

 only in the spiders now under consideration. I am there- 

 fore of the opinion that Tapinocyba should be dropped as 

 a synonym of Troxochrus. As a new genus must be 

 established for hiemalis Bl. and ignobilis Cb. I propose the 

 name Scleroschema and append a brief diagnosis. 



