HABITS OF DONACIA. 31? 



also in Bruchus. The Sagree are beautifully coloured 

 insects, of a green, blue, or a rich purple vinous tint. 

 We find this family containing other genera of a similar 

 form, as Megamerus, a rare New Holland genus ; and 

 Megalopus, from South America ; and we know other 

 African forms yet undescribed. A closely allied genus, 

 Donacia, is, perhaps, one of the most beautiful of the 

 Coleoptera; they are metallic, and of every variety of 

 tint : their larvse feed within sub- aquatic plants ; and it 

 is upon these that the perfect insect is found, for a short 

 time, about midsummer : these may be termed, also, 

 sub-aquatic, for they have the power of walking down 

 water plants considerably beneath the surface it is 

 presumed, to deposit their eggs; and to enable them to 

 retain their hold, we find them furnished with very 

 powerful claws, by which they tenaciously adhere. This 

 is a structure evidently appropriated to this purpose ; for 

 we find it again, but with increased developement, in 

 Macroplea, which has similar habits, and belongs to the 

 same family ; and in Macronychus, which has the habit 

 of clinging to floating wood in strong currents, and be- 

 longs to a group closely allied to Parnus and Dryops. 

 The genus Lema, or Crioceris, will terminate our notice 

 of the monilicorn Coleoptera. These insects seem a con- 

 necting link between Galeruca and the Sagridce; like the 

 former, they are frequently very destructive : the little 

 black larva of one species especially, the C. Asparagi, de- 

 stroying the crops of asparagus, and the C. Merdigera 

 being equally obnoxious to the white lily ; here, however, 

 less detrimental to the results of men's industry and ex- 

 pectations, than in the preceding case. They are elegant 

 and gaily coloured insects. [(278283.) W. E. Sh.] 



