76 Thirty-second Report on the State Museum. 



Gammarus fasciatus has quite a wide distribution, probably occurring 

 throughout most of the Northern States, as it is reported from Maine, Connecti- 

 cut, several localities in New York, from Pennsylvania, Michigan, Illinois and 

 Wisconsin. Its habits of life admit of its existence in the standing water of 

 ponds, as well as in the running water of streams. Of its life-history very little 

 is known; or, indeed, of any of the species of the Gammaridw. Our knowl- 

 edge of them scarcely extends beyond descriptions of the several species, except 

 that the embryology of some of the European forms has been studied and pub- 

 lished. All the Gammaridos are eagerly devoured by fishes. 



The mosses contained a large number of the cases of caddis-worms — Neurop- 

 terous insects of the family of Phryganidoe. A reference to these cases and 

 their occupants will be made hereafter. 



So few of these insects have been reared from their larvae, that it is scarcely 

 possible to identify a species from the examination of its case or its larva — not 

 that they do not afford reliable specific features, but simply because these fea- 

 tures have not been connected with the perfect forms. Had this been done, the 

 caddis-case would, in all probability, indicate its imago as readily as does the 

 cocoon its moth, or the gall its gall-fly. 



The cases contained in the moss were apparently of only two forms. These, 

 together with the larvae taken from them, were submitted to Dr. Hagen, of the 

 Museum of Comparative Zoology, at Cambridge, Mass. — our highest authority 

 in the Neuroptera. 



One of these forms, composed of bits of wood and bark cemented together, 

 and represented in fig. 7 of plate 5, was found by Dr. Hagen to belong to the 

 Limnophilidw — a family comprising the two great genera of LimnophUus and 

 HaUesus. The larva had not been seen by him before, and could, therefore, 

 from its general characters, only be referred with doubt to HaUesus. 



The other form, consisting of small pieces of stone united in a somewhat flat- 

 tened cylindrical case, was referred to the Sericostomidce, and might possibly 

 be that of Dasy stoma numerosum : but the larvae of these groups are so im- 

 perfectly known, that nothing definite could be affirmed of this case. 



The pupae of a species of Cloe — one of the Ephemeridce, were quite abundant 

 in the moss, and actively darting about in the water. Of this genus five species 

 are described in Hagen 's Synopsis of the Neuroptera of North America. 

 They are of small size, measuring, in expanse of wings, from one-fourth (C. 

 pygmosa) to three -fourths of an inch. 



The Ephemeridce are commonly known as May-flies, and from their brief life 

 in their winged state — usually represented as of but a few hours' duration — are 

 sometimes spoken of as Ephemera. Mr. B. D. Walsh, however, has retained 

 living examples of Paling enia bilineata (Say) in his breeding cages, for nearly 

 a week.* 



De G-eer has kept Ephemera vespertina alive for eight days, and Stephens 

 mentions having kept specimens of Cloeon dipterum alive for more than three 

 weeks.! These insects often occur in such immense numbers, that they have 

 been observed "stranded in winrows along the borders of our lakes." The 

 swarms of a European species with white wings (E. albipennis) has been com- 

 pared to a snow storm ; whilst in some parts of Europe where they abound, it 

 is the custom to collect their dead bodies into heaps and use them for manure. 

 The fishes at such times eagerly wait for them ; and so great are the numbers 

 which fall into the water that the fishermen call them manna. (Westwood, loc. 

 cit., p. 29.) 



* Practical Entomologist. Vol. ii, p. 95. 1867. 



t Westwood's Introduction to the Classification of Insects. Vol. ii, p. 27. 



