CLASS I. INSECTA: ORDEPw 1. NEUEOPTERA. 
587 
the pond or stream in Avliicli they live, and these burrows have two openings, so that if the insect 
enters by one it can pass out by the other Avithout the necessity of turning round in its narrow 
domicile. On arriving at maturity the pupae come out of the water, when the perfect insect 
emerges from its case and takes to flight. It is still, however, inclosed in a very delicate pellicle, 
to get rid of which it soon attaches itself by its claws to any object that may be at liand, and 
after a few struggles leave 5 this encumbrance behind it, and flies away. After this last change 
the insect exhibits its brightest colors, and the tails grow to twice their previous length. The 
emerging of these insects from the water appears always to take place in the evening, and as 
the whole of the Ephemeridse in a river appear to arrive at maturity at the same period, they 
genei-ally make their appearance in such countless swarms, for two or three evenings, that the 
eff"ect produced by one species with white wings has been compared to a heavy fall of snow. By 
the next morning the majority of these insects are found lying dead upon the shore in heaps. 
The occurrence of these swarms of May-flies has been observed in d]ff"erent parts of Europe, in 
Holland, France, and Switzerland ; and it appears that the species found in each of these localities 
is distinct from the rest. In Switzerland, indeed, the swarms of two species are on record, one 
inhabiting the Lake of Geneva, and the other the Rhine, near Basle. The common European 
species. Ephemera vulgata, also occurs in profusion for a few days in the rivers frequented by 
it, but not by any means to the same extent as the species just referred to. This and several 
other species of the family are favorite baits for trout. AVe have several species in this country, 
May-Flies being their common name. 
THE PSOCID^. 
This is a family of very minute insects, one species of which, the At^-ojyos pulsatorius, is called 
Death- Watch, on account of its producing a sound like the ticking of a watch. 
THE TERMITIDJd}. 
These animals, often called White Ants, live in vast communities, principally in the hotter 
regions of the earth, where they do incredible damage by devouring almost every thing that 
