412 



REVIEWS. 



While however we admit that Mr. Blackwall has in most instances 

 merely followed earlier authorities, and must be acquitted of any 

 great multiplication of genera on his own account, we may he per- 

 mitted to doubt whether all those which he has adopted are suffi- 

 ciently characterised. "We will take, for instance, Thomisus and 

 Philodromus, placing the characters side by side, as follows : 



Philodromus. 



JEyes disposed on the anterior 

 part of the cephalothorax in 

 two transverse, curved rows, 

 forming a crescent whose con- 

 vex side is in front; they do 

 not differ greatly in size. 



Maxillce inclined towards the lip, 

 and convergent at their extre- 

 mities. 



Lip either triangular or some- 

 what oval. 



Legs so articulated as to be ex- 

 tended laterally ; they are long, 

 and vary in their relative 

 length in different species. 



Thomistts. 

 JEyes disposed on the anterior 



part of the cephalothorax in 



two transverse rows, forming 



either a crescent or a segment 



of a circle whose convex side 



is in front ; they do not differ 



greatly in size. 

 Maxillce inclined towards the lip, 



and pointed at the extremity. 

 Lip either triangular or oval, but 



obtuse at the apex. 

 Legs so articulated as to be ex- 

 tended laterally ; the first and 



second pairs are longer and 



more robust than the third 



and fourth pairs. 



Comparing together the above characters, it must be at once 

 evident that if there is any difference it is not one which can fairly 

 be considered of generic value. According to Walckenaer, indeed, 

 in JPJiilodromus the legs are equal in length, while in Thomisus the 

 two posterior pairs are shorter than the others, but this statement is 

 quite incorrect, as a glance at the figures will show. 



Other similar examples might be given, and therefore we cannot 

 but think that the classification of the Araneidae is very unsatis- 

 factory, and that many of the genera must be abandoned, unless 

 better characters can be given. Mr. Blackwall has probably taken a 

 step in the right direction, in attributing much importance to the 

 comb of hairs characteristic of the Ciniflonidae. Perhaps also the 

 spiders with three tarsal claws might be generically separated from 

 those with two. Mr. Blackwall might, we think, have advan- 

 tageously shortened his specific descriptions, by putting some of the 

 points common to the genus either in the generic description, or, at 

 least, in the general remarks on the group. Eor instance, in all the 

 28 species of Thomisus and Philodromus, except one in which the 

 point is overlooked, he remarks that each tarsus is terminated by two 

 claws. In his remarks on the family Thomisida? he does indeed ob- 

 serve that each tarsus is usually terminated in this manner, but the 

 fact is that all the English species, with perhaps one exception, have 

 this character. 



The total number of species described is 120. Only seven species 



