224 NORTH AMERICAN INSECTS. 



in the water they manufacture a covering around their thin 

 bodies, composed of straw, grass, or pieces of wood, or small 

 woody stems. With these they form a case, open at both 

 ends, in which they are enabled to sail about as if in a row- 

 boat. For this reason, probably, the Romans called this 

 insect Ligniperda, and the Greeks named it Xylophoros 

 (wood-destroyer), but improperly, because they use only old 

 and decayed wood for their purposes. 



These Iarva3, with their transportable cases, are found 

 at the bottom of all those slowly-running brooks, ditches, 

 swamps, and ponds in which aquatic plants grow abund 

 antly, for they are herbivorous and live principally upon 

 the water - crawfoot (Ranunculus aquatilis). The internal 

 part of their case resembles a hollow tube, with two open 

 ings, one for the hind body and the other for the head, which 

 is always protruding from it. They creep on the bottoms 

 of rivers, ponds, etc., by means of their six feet near the 

 neck, which are also kept out of the case, and by which they 

 also drag their case along with them wherever they go. 



Our highly-esteemed friend, Samuel W. Seton, Esq., one 

 of the Superintendents of the Public Schools in the city of 

 New York, and a great amateur and promoter of the study 

 of natural history, presented us with several zoological spec 

 imens, sent to him from Baraka, on the Gaboon River, in 

 Africa. Among these we found some portable cases of 

 water-moths, which were of much larger size than our in 

 digenous species ; but as they will convey a very good idea 

 of the latter, and are themselves somewhat remarkable, we 

 give a representation of one in Fig. 61. 



Figure Gl. 



Grub of tl.c Water-moth. 



