106 Mr. J. Blackvvall's Characters of some 



on the anterior eminence of the cepbalothorax, which is elon- 

 gated and acute. One pair is seated on its summit, a second 

 a little lower, in front, describing with the former a trapezoid 

 whose anterior side is the shortest; and the two other pairs 

 are placed obliquely, one on each side of the frontal eminence. 

 The eyes of the lateral pairs, which are geminated, are the 

 largest, and those of the anterior pair are the smallest of the 

 eight. 



Maxillae strong, convex externally, greatly dilated at the 

 base, where the palpi are inserted, encompassing the lip. 



Lip short, broad, prominent at the apex, and semicircular. 



Legs robust; the anterior and posterior pairs, which are 

 the longest, equal in length in the females; the third pair is 

 the shortest. 



I have conferred upon this singular genus the name of a 

 distinguished living arachnologist, the celebrated Baron Walc- 

 kenaer. 



Walclcenaeria acuminata. 



Cephalothorax oval, gibbous above, with a minute indenta- 

 tion in the medial line of the posterior region, and terminating 

 in an acute prominence before. Pectus oblong heart-shaped. 

 Mandibles vertical, moderately strong, convex in front, and 

 dentated on the inner side. These parts, with the maxilla? and 

 lip, are glossy, and of a dark brownish-black colour. Palpi 

 robust, and without claws ; the third joint is remarkably short, 

 and the fourth and fifth joints are somewhat dilated. Legs 

 hairy, but destitute of spines. Each tarsus has three claws at 

 its extremity; the two superior ones are strongly pectinated, 

 and the inferior one is abruptly inflected near its base. The 

 colour of these organs is bright rufous. Abdomen oval, rather 

 convex above, projecting a little over the base of the cephalo- 

 thorax ; it is sparingly clad with hair, glossy, and deep black. 

 The plates of the spiracles are of a pale yellow colour. 



Length, from the anterior part of the cephalothorax to the 

 extremity of the abdomen, ^ths of an inch ; length of the ce- 

 phalothorax y 1 ^; breadth ^V » breadth of the abdomen Jj; 

 length of a fore leg 3-; length of a leg of the third pair ^. 



Similar to the female in colour, and in the relative length 

 of its legs, but rather smaller than she is, the male has the 

 anterior part of the cephalothorax much more elongated and 

 slender, measuring about 2 J o tn °f an mcn m length ; it is ele- 

 vated vertically, and dilated near the middle and at the apex, 

 the latter dilatation being separated by a transverse groove 

 into an upper and a lower segment, both of which are rough 

 with short strong hairs. On these enlargements the eyes are 

 situated. The third joint of the palpi expands gradually to- 



