Mr. Blackwall's Descriptions of new Species of Spiders. 639 



minent lobe on the outer side ; it is convex and hairy externally, concave 

 within, comprising- the palpal organs, which are highly developed, com- 

 plicated in structure, with a fine spine at their extremity, enveloped in a 

 delicate membrane, and curved in a circular form ; they are of a reddish 

 brown colour. 



Males and females of this species were found on rails near Llanrwst in No- 

 vember 1837, and May 1838. 



25. IValchenaëra pumila. Cephalo-thorace mandibulis maxillis labio sterno- 

 que saturate pedibus palpisque rufescenti-brunneis ; pedum pari 4to 

 pault) longiore, dein Imo, 3tio brevissimo ; abdomine nitente nigro. 



Maris cephalo-thorax antice elevatus obtusus utrinque indentatione 

 instructus. 



Length of the female ys th of an inch ; leng;th of cephalo-thorax ^ ; breadth 

 aV ; breadth of abdomen -^ ; length of a posterior leg ^; length of a 

 leg of the third pair -^. 



Cephalo-thorax oval, glossy, depressed on the sides, which are marked with 

 slight furrows diverging from the upper part to the margins, and having 

 an indentation in the medial line of tbe posterior region. Mandibles 

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

 sternum, wliich is broad and heart-shaped. Maxillœ inclined towards 

 the lip, which is semicircular and prominent at the extremity. These 

 parts are of a dark brown colour, the mandibles and maxillae being the 

 palest. The lateral eyes are the largest, and the anterior ones of the tra- 

 pezoid the smallest of the eight. Legs and palpi reddish brown. Fourth 

 pair of legs rather the longest, then the first, third pair the shortest. 

 Abdomen oviform, convex above, projecting over the base of the cephalo- 

 thorax ; it is thinly clad with hairs, glossy and black. Plates of the spi- 

 racles dull yellow. 



The male is rather smaller than the female, but resembles her in colour 

 and in the relative length of his legs. The anterior part of the cephalo- 

 thorax is elevated, but obtuse, with an oblong indentation on each side, 

 extending backwards from the lateral eyes. Fourth joint of the palpi 

 shorter than the third ; it is produced at the extremity, on the inner side, 



