NEUROPTERA. 



231 



lobe ; the maxillary palpi are well developed, and furnish characters 

 which are much used in classification ; the labium is usually well 

 developed, and bears three-jointed palpi. 



The females deposit their eggs in masses enveloped in a gelati- 

 nous covering. These are often found adhering to the end of the 

 body in captured specimens. It is supposed that these eggs are 

 usually deposited on aquatic plants ; but it is known that in some 

 cases the females descend below the surface of the water to oviposit. 



The larvae are long, cylindrical, soft-bodied, and furnished with 

 six well-developed thoracic legs and a pair of anal legs. The abdo- 

 men bears a greater or less number of hair-like tracheal gills. These 

 larvae protect themselves by building a case about the body, in which 

 they live during the larval and pupal stages. These cases vary 

 greatly in form, and in the materials used in their construction ; but 

 in general those made by the larvae of any given species are very 

 similar. 



One of the most interesting topics which a young entomologist 

 can take for study is the habits of these insects. The larvae can be 

 easily found throughout our country. Many species can be kept in 

 aquaria; but others, those that live in swiftly-flowing water, must be 

 observed in their native haunts. I will indicate a few of the general 

 features in the economy of these insects. The facts given here can 

 be easily supplemented by any careful observer. 



Among the simplest of the various forms of houses built by 

 caddice-worms are those made by certain species that live under 

 stones in rapid streams. These consist merely of a few pebbles 

 fastened to the lower surface of a larger stone by threads of silk. 

 In the space between these stones the worm makes a more or less 

 perfect tube of silk, within which it lives. Very little respect for 

 the architectural skill of these builders is commanded by their rude 

 dwellings. But if one looks a little farther, something will be found 

 that is sure to excite admiration. The dweller within this rude re- 

 treat is a fisherman ; and stretched between two stones near by can 

 be seen his net. This is made of threads of silk extending in two 

 directions at right angles to each other, so as to form meshes of sur- 

 prising regularity. It is as if a spider had stretched a small web in 

 the water where the current is the swiftest. In the streams about 

 Ithaca these caddice-worm nets are very abundant. They occur in 

 the rapids between stones, but are to be found in greater numbers 

 along the brink of the falls. Here they are built upon the surface 

 of the rock, in the form of semi-elliptical cups, which are kept dis- 



