with Characters of Six New Genera. 93 



transformations, are described in the third volume of the Lin- 

 naean Transactions. The whole group appears to be entirely 

 herbivorous in its habits. In our own country they are chiefly 

 partial to thistles and marsh marigolds, occurring also on the 

 water-mint and other aquatic plants. The thistle, when much 

 infested by the larvae early in the summer, occasionally appears 

 as if scorched by fire ; the marsh marigolds turn perfectly 

 black, and in some years, when attacked by these parasites, 

 they are not only greatly impoverished by them, but are en- 

 tirely destroyed. The number of European tortoise beetles 

 known is about forty species. It is difficult however to state 

 the numbers accurately, as great difference of opinion exists 

 as to what are really species ; their synonymy is perplexing, 

 and, as the range which some species enjoy is very extensive, 

 there is consequently an increase of varieties, arising probably 

 from difference of food, climate, temperature, and soil. In- 

 stead of entering accurately into their geographical distribu- 

 tion, I shall merely state the numbers mentioned by authors, 

 and then add some general remarks on the whole. Linnaeus, 

 in his f Systema Naturae,' gives us but 23 species, Olivier 105, 

 Fabricius, after separating Imatidium, 119. The Baron De 

 Jean, including the latter genus, gives us in the first Cata- 

 logue 109, and in his last about 400. In my own collection 

 there are 500 species, and at least 200 more have fallen under 

 my notice ; and as Cassida is a group which has been greatly 

 neglected, it will eventually be found much more numerous 

 than is at present supposed. Out of the 500 now known, 400 

 belong to the New World. Perhaps scarcely 40 will be found 

 mentioned in catalogues and works as inhabiting Africa, and 

 less is the number described from Asia, even including the 

 extended continent of Australia. Professor Perty, in his c Con- 

 spectus Coleopterorum Indiae Orientalis/ mentions but 22 

 from Asia. From the above statement, therefore, it will ap- 

 pear that the New World affords a very large proportion of 

 the Cassidoidea known. As to the European species, there is 

 not much reason to think that they will prove to be much 

 more numerous than at present. As to African Cassidce, they 

 will eventually be found to be considerably more numerous 

 than the European species, and I am inclined to think that 



