IIEV. O. r. CAMBRIDGE ON NEW SPIDEllS. 271 



A single specimen of this remarkable spider (contained in a 

 small collection of interesting species made by Mr. G-. H. K, 

 Thwaites, of Ceylon) is in the Hope Coll., University Museum, 

 Oxford. 



This genus, which appears to have escaped the attention of 

 arachnologists in general, was established by Professor West- 

 wood some years ago upon a very remarkable adult S specimen 

 received by him from Malabar {Phoroncidia aculeata, Westw. 

 Zool. Journ. vol. v. p. 452, pi. xxii. fig. 19). 



The similarity, at first sight, of this spider to those of fam. 

 Epeirides, genera Gasteracantha and Acrosoma, appears to have 

 led Professor "Westwood to the conclusion that it also belonged 

 to the same family ; the form, however, of the cephalothorax, as 

 well as the structure of the maxillse and labium, would seem to 

 place it more properly in the family Theridides, to which 

 family it is also closely united by the position of the eyes and 

 the relative length and slenderness of the legs. 



The genus PTioroncidia, in fact, appears to bear the same rela- 

 tion to the family Theridides as Gasteracantha and Acrosoma &c. 

 to the family Epeirides. No notice appears to have been taken 

 of the habits of FJwroneidia aculeata or of the present species 

 P. Thwaitesii ; but, if I am right in supposing it to belong to the 

 Theridides, I should expect to hear of its forming (not as is the 

 habit of all the Epeirides) a geometric web, but an irregular one 

 among the shoots and branches of low trees and plants. The two 

 species, P. aculeata and P. Thwaitesii, strikingly different in 

 colour, markings, and number of spines, resemble each other 

 very nearly in form of cephalothorax, position of eyes, and struc- 

 ture and form of maxillae and labium. 



Family THOMI SIDES. 

 Genus Thlaosoma, nov. gen. 



Characters of genus : — 



Cephalothorax tuberculate-spinous ; caput elongate, but not ele- 

 vated ; hinder portion of thorax much higher than caput. 



Abdomen globular and elevated, with a deep fold or impression 

 on hinder part, as if shrunken in or bruised inwards. 



MaxillcB short, strong, slightly inclined to labium, obliquely 

 truncate on outer sides at extremity, outer corners rounded oiF, 

 inner ones pointed. 



