100 Mr. Black Willi on a new Genus and 



copper, nianpraiiese. In certain cases, however, tliis would not 

 be convenient unless the quantity of the above metals was in- 

 considerable. The oxides of manganese and cobalt, from their 

 ready solubility, might easily be thus separated from iron. 



R. H. Brktt. 



XXII. Characters of a new Germs and some undescribed Species 

 tj/'AraneidoB. Bi/ John Blackwall, Esq., F.L.S., t^c* 



Tribe, Inequitelje, Latreille. 

 Genus, Deletrijc. 



EYES six in nuniber, unequal in size, aggregated in pairs on the anterior 

 I part of the cej)halothorax'; two pairs are phiced laterally, their an- 

 terior eyes being the largest, and their posterior ones the sujaliest of the 

 six; the third pair is intermediate, the eyes which constitute it being oval, 

 and contiguous ; the entire group f^rms two triangles united by the apices 

 composed of the oval-shaped eyes. 



MaxilUe enlarged at the base, externally, where the palpi are inserted, 

 and slightly so at the extremity ; inclined towards the lip. 



Jjip short, triangular, and pointed. 



Legs long, and moderately robust; the fourth pair is the longest, then 

 the first, which a little exceeds the second in length, the third pair is 

 the shortest. Tarsi triarticulate, the terminal joint being very short and 

 slender. 



Deletrix exilis. 



This minute spider has the cephalothorax oval, glossy, convex, pointed 

 before, abruptly sloping behind. Mandibles slender, conical, vertical. 

 Pectus broad, heart-shaped, convex, provided with some scattered hairs. 

 These parts, with the n)axillas and lip, are pale red. Legs supplied with 

 liairs, and with two rows of spines on the inferior surface of the tibiae and 

 tarsi, directed down the joints, those on the first and second pairs being the 

 inost conspicuous ; they are of a pale yellowish brown colour, the thighs 

 liaving a tinge of red. The palpi resemble the legs in colour, and are 

 abundantly supplied with long hairs, particularly at the extremity. Tarsi 

 triarticulate ; the terminal joint, which is very short and slender, has two 

 curved, pectinated claws at its extremity, and a small brush beneath then). 

 Abdomen oval, thinly covered with hair, projecting over the base of the ce- 

 f)halothorax ; its colour is yellowish brown, wi(h a band extending along 

 each side of the medial line on the upper part, some irregular, oblique stripes 

 on the sides, and a longitudinal band occupying the middle of the under 

 part, of a browner hue. Plates of the spiracles pale yellow. Spinning mani- 

 niulai prominent, and of a pale yellowish white colour. 



Length, from the anterior part of the cephalothorax to the extremity of 

 the abdomen, -rV^h of an inch ; length of the cephalothorax ;,'^; breadth 

 ■^r ; breadth of the abdomen 3V; length of a posterior leg-^V; length of 

 a leg of the third pair -tt. 



All the specimens of this spider which I have captured were females, 

 Hiid were discovered under stones and blocks of wood, at Crumpsall Hall, in 

 September, 1836. Being ignorant of the oeconoujy of the species, I have 

 placed it, i)rovisionally, in the tribe hiequitdce, as it bears a close resem- 

 bbmce to the spiders belonging to the genus Sci/todes in the structure of 

 the mouth. 



• Communicated by the Author. 



