Chrytomelinn.] PHYTOpaAGA. 299 



posed of five ventral segments ; the general form is oval and convex, and 

 many of the species are very brilliantly coloured (hence their name), but 

 they differ very considerably in both these characters. In the following 

 table I have entirely dropped the characters drawn from the tarsal joints, 

 and have adopted more simple ones which may not in all cases be of 

 universal application, but will for the most part enable the British 

 genera to be distinguished with more or less ease. 



I. Anterior coxal cavities closed behind ; inetasternum 



very short TlMARCHA, Latr. 



II. Anterior coxal cavities open behind. 



i. Prosternum without distinct process behind ; thorax 



margined at base; tibia? produced into a tooth 



externally at apex GASTHOIDBA, Hope. 



(Oastrophysa, lledt.) 

 ii. Prosternum with a distinct process behind. 



1. Elytra with their inner posterior margin very 

 finely ciliated ; * form ovate or short ovate and 

 convex ; abdomen with the first ventral segment 



longer than the metasternura CHKYSOMEU, L. 



2. Elytra with their inner posterior margin not 



ciliated. 



A. Tarsal claws toothed. 



a. Tibiae, at least the posterior pair, produced 

 externally into a more or less strong tooth at 



apex PHTTODECTA, Kirby. 



(Oonioctena, Redt.) 



b. Tibiae not produced externally into a tooth at 



apex PBTLLODECTA, Kirby. 



(Phratora, Chevr.) 



B. Tarsal claws simple. 



a. Elytra not punctured in distinct rows, usually 



confusedly punctured, 

 a*. Elytra with the epipleursB not sharply 



inflexed, almost flat ; size larger .... MBLASOMA, Steph. 



(Lina, Redt.) 

 b*. Elytra with the epipleurso strongly and 



sharply inflexed against the under-side ; 



size smaller (facies of Phcedon) .... PLAGIODEEA, Redt. 



b. Elytra punctured in distinct rows. 



a*. Form short oval and convex PH.EDOX, Latr. 



b*. Form oblong, elongate-oblong, or oblong 



oval. 

 f. Thorax transverse, not margined at base; 



form shorter HTDBOTHA88A, Thomi. 



bf. Thorax subquadrate, margined at base ; 



form longer PBABOCUBIS, Lair. 



TIM ARC HA, Latreille. 

 This genus contains about a hundred species, which are chiefly confined 



* This character in some specie* is very marked, under a high magnifying power, 

 but in others is less evident and sometimes requires the removal of the eljtra for its 

 proper examination. 



