63fi Mr. Blackwall's Descriptions of new Species of Spiders. 



posterior region, with an exceedingly minute indentation in the medial 

 line. Mandibles conical, armed with teeth on the inner surface, and in- 

 clined towards the sternum, which is heart-shaped and glossy. Maxillae 

 strong, and inclined towards the lip, which is semicircular and prominent 

 at the extremity. These parts, with the legs and palpi, are brown, the 

 mandibles, lip, and margins of the cephalo-thorax being the darkest. 

 First and fourth pairs of legs, which are the longest, equal in length, third 

 pair the shortest. Abdomen oviform, convex above, projecting over the 

 base of the cephalo-thorax ; it is thinly covered with hairs, glossy, and 

 very dark brown, or brown black. Plates of the spiracles brown. 



The male, though smaller than the female, i-esembles her in colour and 

 in the relative length of his legs ; but differs from her in having an in- 

 dentation on each side of the anterior part of the cephalo-thorax, imme- 

 diately behind the lateral eyes. The fourth joint of the palpi, which is 

 rather shorter and stronger than the third joint, projects an acute, pro- 

 minent apophysis from its extremity, in front ; fifth joint oval, convex 

 and hairy externally, concave within, comprising the palpal organs ; they 

 are moderately developed, not very complicated in structure, rather pro- 

 minent, and of a red-brown colour. 



Numerous specimens of this very minute spider were procured on rails near 

 Llanrwst, in December 1836, and January 1837. 



23. IValckenaera humilis. Nigricans ; pedibus palpisque rufo-brunneis. 



Maris pedes posteriores anterioribus paulo longiores ; cephalo-thoracis 

 pars anterior elevata truncata apice pilis plurimis brevibus instructa. 



Length of the female Yffth of an inch ; length of cephalo-thorax -^ ; breadth 

 ^ ; breadth of abdomen ^ ; length of an anterior leg ^ ; length of a 

 leg of the third pair -^. 



Upper part of the cephalo-thorax glossy, convex, particularly behind the eyes, 

 depressed in the posterior region, with an indentation in the medial line. 

 Mandibles conical, armed with teeth on the inner surface, and inclined 

 towards the sternum, which is broad, heart-shaped, convex and glossy. 

 These parts, with the maxillae and lip, are brown-black, the mandibles 



