302 Mr. J. Blackwall on some species of Araneidea. 



gans, which are very highly developed, very complicated in struc- 

 ture, and of a red-brown colour. Abdomen glossy, sparingly 

 supplied with hairs, oviform, convex above, projecting over the 

 base of the cephalo-thorax ; upper part yellowish white, with a 

 series of obscure, dark, angular lines, whose vertices are directed 

 forward, extending along the middle, but least conspicuous on its 

 anterior half; sides and under part pale yellowish brown. The 

 plates of the spiracles are dark yellowish brown, and the trans- 

 verse fold between them is prominent. 



A male of this species was discovered among the grass of a 

 pasture at Oakland in September 1845. 



Family THERiDiiDiE. 



Genus Theridion, Walck. 



5. Theridion versutum. 



Length of the male ^ths of an inch ; length of the cephalo- 

 thorax ± ; breadth TT ; breadth of the abdomen y 1 ^ ; length of an 

 anterior leg J ; length of a leg of the third pair ^. 



Cephalo-thorax oval, slightly compressed before, convex, glossy, 

 having an indentation in the medial line : mandibles powerful, 

 conical, vertical : both parts are brown faintly tinged with red. 

 Maxillae convex at the base, pointed at the extremity, and greatly 

 inclined towards the lip, which is semicircular : sternum heart- 

 shaped : these parts are brown tinged with yellow, the extremi- 

 ties of the maxillae being yellowish white. Legs long and slender ; 

 they are provided with hairs and are of a pale yellowish brown 

 colour; first pair the longest, then the fourth, third pair the 

 shortest. Each tarsus is terminated by three claws; the two 

 superior ones are curved and pectinated, and the inferior one is 

 inflected near its base. The four intermediate eyes form a square, 

 the two anterior ones, which are the darkest and rather the 

 smallest of the eight, being placed on a prominence ; the other 

 four are disposed in pairs on the sides of the square, the eyes 

 constituting each pair being contiguous and seated on a tubercle. 

 Palpi pale yellowish brown ; the radial is larger than the cubital 

 joint and elongated on the outer side ; this elongation is rounded 

 at the extremity and applies very closely to the digital joint, 

 which is oval, convex and hairy externally, concave within, com- 

 prising the palpal organs ; they are moderately developed, com- 

 plicated in structure, with a prominent process on the inner side, 

 and a strong curved spine at the extremity, whose slender point 

 is in contact with a delicate white membrane ; their colour is 

 reddish brown. Abdomen oviform, thinly covered with hairs, 

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

 upper part is black with a large, white, crescent-shaped mark at 



