332 Mr. J. Blackwall on new species of Araneidea. 



by three claws ; the two superior ones are curved and pectinated, 

 and the inferior one is inflected near its base. The palpi are 

 short, and resemble the legs in colour, but are only slightly 

 marked with brown ; they have a curved and minutely pecti- 

 nated claw at their extremity. The abdomen is oviform, thinly 

 clothed with hairs, very convex above, projecting over the base 

 of the cephalo-thorax ; it is pointed towards the spinners, and 

 has a bold conical prominence in the medial line of the upper 

 part, at about one-third of its length from the anterior extre- 

 mity ; its colour is brown obscurely freckled with yellow-brown, 

 the under part being somewhat the palest ; and a fine brownish- 

 black line, which is broadest immediately before the conical pro- 

 minence, extends along the middle of the upper part ; the sexual 

 organs are moderately developed, and present two minute glossy 

 protuberances. 



I have named this very remarkable spider in compliment to 

 Eyton Williams, Esq., of Denbigh, to whom I am obliged for it 

 and for numerous highly interesting specimens of Arachnida 

 and Insecta captured by him in Pernambuco. By its external 

 structure it appears to be most nearly allied to the species be- 

 longing to the genus Uloborus, more especially to the Uloborus 

 zosis of Walckenaer ; but, as it is provided with a calamistrum 

 and a fourth pair of spinners, which must exercise an important 

 influence on its oeconomy, it is evident that it should occupy a 

 place in the family Ciniflonidce ; I have therefore proposed a new 

 genus for its reception, to which Uloborus zosis may be trans- 

 ferred should it possess a calamistrum and a fourth pair of spin- 

 ners, which I strongly suspect to be the case ; indeed Walckenaer 

 had thought of constituting a genus of it, but ultimately placed 

 it in that of Uloborus, 



Family TheridiidjE. 



Genus Arte ma, Walck. 



Artema convexa. 



Length of the female T %ths of an inch ; length of the cephalo- 

 thorax | ; breadth j ; breadth of the abdomen J ; length of an 

 anterior leg ly 9 ^ ; length of a leg of the third pair 1£. 



The legs are very long, slender, provided with hairs and fine 

 spines, and are of a pale yellow-brown colour ; a dark brown 

 annulus occurs near the yellowish-white extremity of the femora 

 and tibise, and the genual joint has a dark brown hue; the first 

 pair is the longest, then the fourth, and the third pair is the 

 shortest ; each tarsus is terminated by three claws ; the two 

 superior ones are curved and deeply pectinated, and the inferior 



