30 The Irish Nahiralisi. February, 



The PALPAL ORGANS are very distinct and complex. 

 The dens medius is of extraordinary size and comphcatcd 

 shape. It rises from the middle of the palpal organs and 

 nms as a broad plate downwards and inwards. The dens 

 posticus is small and inconspicuous. The structure of 

 these organs seems quite unlike that of any other species. 



The FEMORA of the walking legs bear a number of hair- 

 carrying prominences. In the case of the two posterior 

 pairs these are very small granulations. On the second pair 

 a median row of granulations are larger and might almost 

 be called denticles, whilst on the first pair these are of 

 enormous size and form a series of very large teeth. They 

 still, however, carry hairs, which usually rise from some 

 place not quite at the apex. 



The VULVA of the female is fairly characteristic, but 

 only two specimens are as yet to hand, and it may be found 

 to be a variable character. In these specimens the posterior 

 border forms a rather characteristically shaped ridge, which, 

 if always present, would enable one to identify the species 

 fairly easily. The vulva of E. longipalpis Sand, is the one 

 which approaches it most closely, and a further series of E. 

 Wclchii should be obtained for comparison. 



In the male sex E. Wclchii resembles E. spinosa Camb., 

 and differs from all the other British species in possessing 

 a curved patellar apophysis, very strong teeth on the outer 

 borders of the falces, and strong hair-bearing teeth on the 

 femora of the first and second pairs of legs. It is, however, 

 impossible to confuse it with E. spinosa. In a male of that 

 species measured by me the patella of the palpus was .40 

 mm. in length, whilst its apophysis measured from the 

 outer side (inward curve not included) was only .21 mm. 

 long. This apophysis besides being much shorter is directed 

 much more forwards, and its tip is curved inwards and 

 slightly backwards. The article, too, exhibits small lateral 

 denticles. These occur on both sides and are mostly very 

 small, but two on the inner side attain quite respectable 

 dimensions. A further difference exists in the femora of the 

 pali)i. In E. spinosa these bear beneath several imperfect 

 rows of small denticles which are placed on the proximal 

 three-quarters of the joint. They do not decrease in size 

 from the base towards the apex. Some are sharp and some 



