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



20. fValchenaera bifrons. Mas saturate brunneus ; pedibus palpisque flaves- 

 centi-rufis; cephalo-thorace antic^ protuberantia magna perpendicular! 

 obtusa longitudinaliter bilob&. 



Length of the male ^^th of an inch ; length of cephalo-thorax -^ ; breadth ^ ; 

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

 the third pair -j^. 



On the anterior part of the cephalo-thorax, which is compressed, there is a 

 large, perpendicular, obtuse eminence, divided into two Jobes at the sum- 

 mit by a longitudinal furrow ; the posterior region is depressed, and the 

 frontal margin very prominent. Mandibles small, conical, armed with 

 teeth on the inner surface, and inclined towards the sternum, which is 

 broad and heart-shaped. Maxillae inclined towards the lip, which is 

 semicircular and prominent at the extremity. These parts are dark 

 brown, the lip and frontal eminence of the cephalo-thorax being the 

 darkest. Legs and palpi yellowish red. First and fourth pairs of legs, 

 which are the longest, equal in length, third pair the shortest. Four eyes, 

 situated on the anterior part of the frontal eminence, form a square ; the 

 two superior ones are seated on a minute tubercle, and the inferior ones 

 are the smallest of the eight ; the other four are disposed in pairs on the 

 sides of the eminence, near the front, those of each pair being contiguous. 

 The fourth joint of the palpi, which is much shorter than the third, pro- 

 jects a small, slightly curved apophysis from its anterior extremity, on the 

 outer side ; the fifth joint is oval, convex and hairy externally, with an 

 indentation on the outer side of the upper part ; it is concave within, 

 comprising the palpal organs, which are highly developed, complicated in 

 structure, with a curved, black spine at the extremity, enveloped in a de- 

 licate membrane, and are of a reddish brown colour. Abdomen oviform, 

 convex above, projecting over the base of the cephalo-thorax ; it is thinly 

 covered with hairs, glossy, and dark brown. Plates of the spiracles dull 

 yellow. 



The spider described above was captured by T. Glover, Esq., of Smedley, 

 near Manchester, in June 1838, among coarse herbage in Gwydir woods, near 

 Bettws y Coed, Caernarvonshire. 



