COLEOPTERA. — CRIOCERIDiE. 373 



elongate triangular form ; the posterior femora are often much incras- 

 sated. The species are generally found upon the leaves or stems of 

 various plants, some preferring the aquatic, and others the liliaceous, 

 tribes. The larva? of those species which frequent the former feed 

 upon the inner substance of their stems ; whilst the latter are exposed, 

 feeding upon the leaves, but covering themselves with a sort of 

 mantle, formed of their own excrement. 



Amongst these insects Donacia, is most nearly allied to the Lcptu- 

 rida;, the larva being an internal feeder, and the organs of the mouth 

 being not very dissimilar. 



Latreille subdivides this division into two groups : Sagrides 

 and CRrocERiDES ; the former having the mandibles terminated by an 

 acute point, and the lower lip bilobed ; and the latter having the man- 

 dibles truncate at the tip, with two or three acute teeth, and the 

 lower lip entire. It will, however, be more convenient to regard them 

 as subfamilies ; the Eupoda being thus composed of a single family, 

 Criocerid^ Leach. 



The species of the genus Donacia (^/V/. 4-5. i. Donacia crassipes, 

 45. 2. labrum, 45. 3. mandible, 45. 4. maxilla, and 45. o. labium, of D. 

 Menyanthidis) are generally of brilliant metallic tints; and many of 

 them arc clothed beneath with a fine silky dou-n, which must be of 

 service in protecting them from the action of the water when they 

 happen to fall from the plants upon which they reside (as the Scro- 

 phularia, Nymphsea, &c.), and in the stems of which the larvte take 

 up their abode. They are naked in this state ; but no precise descrip- 

 tion has been given of these larva*, which, from the osculant character 

 of the genus, it is very desirable should be made known. The pupge, ac- 

 cording to M. Ad. Brongniart, are inclosed in silken cocoons, attached 

 to the roots, filaments, or surculi of these water-plants, on one side 

 only, forming knots along the stems. A correspondent of the Mag. Nat. 

 Hist, No. 12., has published some observations upon certain egg-shaped 

 transparent brown cases, found in the winter, close to the root of 

 Arundo Phragmites, and considered as the winter quarters of Do- 

 nacia micans, the perfect insect being found therein, but which were 

 evidently the construction of the larviv, serving as cocoons. In Mr. 

 Kirby's collection, presented to the Entomological Society, one of 

 these cocoons is preserved. 



Reaumur (iW>«o«Ve5, vol. iii. pi. 17. mem. 7.) has given us an inter- 

 esting account of the habits of the lily beetle, Crioceris merdigera 



B B 3 



