90 LEPIDOPTERA. 



in repose, forming a well defined triangle ; a long 

 sharp snout, formed by the elongated palpi, is charac- 

 teristic of many moths in this group, which includes 

 Meal-worm moths. Pearl moths, from the peculiar lustre 

 of the wings. These Snout moths may be seen in great 

 numbers in gTass fields intended to be mown, sporting 

 themselves in the sunshine, and settling on the bents of 

 grass, head-downwards, where they remain stationary and, 

 owing to their inconspicuous colouring, difficult of de- 

 tection. The China-mark moths {Hydrocampa) belong 

 to this same group. This genus is remarkable in the 

 fact of the larvae being aquatic, hence the Greek name, 

 ** Water-caterpillar," which distinguishes it. 



" Of all the Lepidoptera the Hydrocampida3 are per- 

 haps the most extraordinary, so far as their methods of 

 life are concerned. The moths fly and enjoy the air as 

 much as any others, and cannot be distinguished from 

 those whose caterpillars live on dry land. Their 

 breathing apparatus is like that of other moths, and 

 they have the habits of the other night-flyers. But 

 the caterpillars live in the water, surrounded by a great 

 bubble of air, and others positively have gills or bran- 

 chia3, and are surrounded and bathed by water. Tliis 

 is a most extraordinary fact, for the moths which are 

 produced by metamorphosis from these caterpillars re- 

 semble each other to a great extent, and it shows how 

 slight the distinction may be between aquatic and air- 

 breathing animals, and how nearly the origin of the 

 separate conditions maybe allied."* The pupa is en- 

 closed in a cocoon, the case of the larva. The China 



* Transf. of Insects, p. 139. 



