widescribed Genera and Species o/*Araneicli£. 107 



wards its anterior extremity; the fourth joint is short, termi- 

 nating in three apophyses, and on the upper part of the inner 

 apophysis, which is longer than either the exterior or the inferior 

 one, and is curved outwards, a small prominence occurs ; the 

 fifth or terminal joint is somewhat oval, convex externally, 

 concave within, comprising the sexual organs, which are black, 

 with a tinge of red ; they are highly developed and compli- 

 cated in structure, having a strong spiny process on the outer 

 side curved into a circular form. 



My brother, Mr. Thomas Black wall, discovered this re- 

 markable spider in the month of October 1832, under stones 

 and on rails in the township of Crumpsall, near Manchester. 



Walckenaeria cristata. 



In colour this species is similar to Walckenaeria acuminata, 

 with the exception of the legs, which have a deeper shade of 

 rufous; but in external structure it presents several obvious 

 points of difference. The anterior part of the cephalothorax is 

 less elevated and acute, and the pectus is shorter and broader 

 proportionally. 



Length, from the anterior part of the cephalothorax to the 

 extremity of the abdomen, TT th of an inch ; breadth of the ab- 

 domen X. The fore and hind legs, which are the longest 

 and equal in length, measure T l m and the third pair is the 

 shortest. 



The relative length of the legs is different in the sexes ; the 

 male has the fourth pair the longest, measuring Jth of an inch ; 

 then the second, the third pair being the shortest. The an- 

 terior eminence of the cephalothorax is shorter and very much 

 stronger than the same part in the male of Walckenaeria acu- 

 minata ; it is divided into two segments at the summit by a 

 deep transverse groove, and each is surmounted by a tuft of 

 fine hair inclined towards the groove and forming a crest. 

 One pair of eyes is seated on the hinder part of the posterior 

 division of the eminence, near its summit, and another pair is 

 situated near the summit of the anterior division, in front, de- 

 scribing with the former a trapezoid whose shortest side is 

 before ; the other eyes are disposed in pairs, one on each side 

 of the frontal prominence, and are geminated. The eyes of 

 the lateral pairs are the largest, and those of the anterior pair 

 the smallest of the eight. The third joint of the palpi is en- 

 larged at its anterior extremity; the fourth presents two apo- 

 physes, one small, projecting underneath ; the other, which is 

 much larger and tapers to a point, curved outwards, being si- 

 tuated in front ; the fifth joint, and the anterior apophysis of 

 the fourth are expanded laterally; they are convex externally, 



P2 



