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, pen 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 ylopheros 
(wood-destroyer), but improperly, because they use only old 
and decayed wood for their purposes. 
These larve, 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, ete., 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 61. 


Grub of the Water-moth. 
