368 On a new Fossil Spider (Eoatypus Woodwardii) . 



width of the cephalothorax at the caput 2'25 ; width of 

 cephalothorax from margin to margin across the middle 3*5 

 millim. ; length of palps 2 millim. Both palps are represented 

 by rather thin lines, showing slight marks of joints, and on 

 one palp is a suggestion of a terminal bulb which might indi- 

 cate it to be a young male. 



The caput and median part of the cephalothorax as viewed 

 from the cast are well elevated and defined ; the cephalo- 

 thorax narrows towards the abdomen. But in the original 



Fia 1 



Fig. 2. 



Fig. 1. — Eoatypus Woodwardii, X 4. 



Pig. 2, — Ditte, X 4, Outline side view of body. 



impression in the rock and less distinctly on the casts there 

 appear outlines on either side of the margin of the cephalo- 

 thorax, as though by pressure those parts had been flattened, 

 and only the caput and a part of the dorsum of the cephalo- 

 thorax along the median line had withstood the pressure and 

 had been pushed upward into the matrix by the same. These 

 outlines are visible, but not so distinct in the plaster cast. 

 It is at this point that one experiences difiiculty in deter- 

 mining whether the specimen is related to Attus or to Atypus. 

 If the broader marginal markings are impressions of the 

 original cephalothorax, the inference would be that the spider 

 represented by this fossil belonged to the Atypin^. That 

 such is the case I am strongly inclined to believe, both on 

 the ground just named and the characteristics of the man- 

 dibles as well as the general facies of the impression and 

 cast (see fig. 1) *. In the absence of the characteristic eyes 

 * This figure has been drawn from the cast and compared carefully 

 with one kindly made for me in the Geological Department of the British 

 Museum, and furnished by the Keeper, Dr. Woodward. 



