CI1RYS0MELID-E. 



179 



completed one volume of the Fauna of British India containing 

 the first portion of the family, and hoped to complete it in three 

 volumes ; in the part already published he has dealt with 

 903 species, so that the number with which he was acquainted 

 must be about 2700 to 3000, and this probably represents only a 

 comparatively small proportion of the whole number of species 

 existing in the region. 



We have before alluded to the difficulty of distinguishing 

 between the Chrysomelid.e and the Cerambyoid;e in several 

 groups. Mr. Jacoby states that it may be taken as a general rule 

 that in the LoistgicortnTA " the shape is very elongate, the head 

 projecting and prominent, the eyes oblique and more or less 

 divided and the antennae peduncular, these organs being at the 

 same time rigid and tapering at the apex. All these structures 

 are not as a rule found in the Chrysomelid.e.*' 



The following is a key to the divisions adopted by Mr. Jacoby 

 in his work (I. c. p. 3) : — 



I. Mouth placed anteriorly, 

 i. Antennre widely separated at base ; elytra of 

 hard texture. 



1. Intermediate ventral segments not medially 



constricted ; pygidium not exposed. 



A. Thorax without distinct lateral margins, 



head produced, eyes prominent, prosternum 

 exceedingly narrow Eupodes. 



B. Thorax with distinct lateral margins (rarely 



without), head not produced, eyes not 

 prominent, prosternum broad Cyclica. 



2. Intermediate ventral segments constricted ; 



pygidium usually exposed Camptosomes. 



ii. Antennae not widely separated at base, generally 

 closely approximate ; elytra more or less soft 



in texture Trichostomes. 



II. Mouth not normal, small, hidden or nearlv so ... . Cryptostomes. 



1. Eupodes. — This group contains the Sagriis"^;, Criocerinje, 

 and Do^aciiisle, which are all represented in India. The 

 Sa.gri2tje are large and brilliant insects with the posterior femora 

 very strongly thickened ; very little is known of their habits. 

 Donacia is more characteristic of temperate climates and only 

 four species have been recorded from the Indian region ; it is 

 chiefly remarkable for the peculiar habits of the larvae, which live 

 under water and apparently suck air from the aquatic plants by 

 means of two spines at the apex of the body, which are 

 believed to have a stigma at the base of each, although this 

 seems hardly proved. The Crioceri^e are chiefly represented 

 in the Indian fauna by the genus Lema, of which no less than 118 

 have been found in the region. The larva of Orioceris has 

 the power of covering itself entirely with its excrement, but 

 it has no special process for supporting this; the covering does not 

 adhere closely to the body of the larva and can, indeed, be thrown 



