242 Rev. O. P. Cambridge on new 



their base on the inner sides. M. Simon, however, determines 

 them without any doubt to be examples of A. Blackwalli, in 

 which this peculiar form of the falces is a leading character- 

 istic. One of these examples was found by myself in the 

 Island of Portland ; the other was received from the Isle of 

 Wight, where it was found by Mr. Pearson and kindly sent to 

 me among females of A. piceus, Sim. 



Atypus Beckii, sp. n. PI. VIII. fig. 1. 



Adult male, length 4f lines. 



This spider is nearly allied to A. piceus (Sulzer) ; it appears, 

 however, to be larger and rather broader in proportion, and it 

 differs in the form of the cephalothorax and falces, as well as 

 in the structure of the palpal organs and size and relative 

 position of the eyes. 



The whole of the fore part, including the legs and palpi, 

 are of a rich deep red-brown colour ; the abdomen is black, 

 with the characteristic coriaceous patch on the fore part of the 

 upperside of a large size and dark reddish brown colour ; the 

 hinder slope of the caput is rather abrupt and rounded in its 

 profile-line : the central part of the ocular area is prominent, 

 and, looked at in profile, full and rounded in front (much more 

 so than in A. piceus) ; looked at from above its fore extremity 

 is of a blunt angular form and projects a little beyond the 

 margin of the clypeus, while in A. piceus the fore extremity 

 is round and does not reach to the clypeal margin, and its 

 colour is black ; the thorax is flattened and the normal inden- 

 tations strong. 



The eyes are in the usual position, the central pair occu- 

 pying the upper part of the large central ocular tubercular 

 prominence ; these two eyes are smaller than those of the 

 corresponding pair in A. piceus, and the interval between 

 them exceeds an eye's diameter by nearly or quite one half, 

 while in A. piceus the interval no more than equals a diameter, 

 certainly does not exceed it. The lateral groups are also fur- 

 ther from the central pair in the present spider than in A. 

 piceus, forming, when looked at from above, a transverse 

 oblong area of far greater extent than in this latter species. 



The falces, though of the same general character as in A. 

 piceus, are rather longer and stronger, though perhaps not 

 quite so prominent at their base on the upperside. 



The palpi, although very similar in general character and 

 appearance to those of A. piceus, show a strong and decided 

 difference on a comparison of the palpal organs ; this distinction 



