84 Thirty-second Report on the State Museum. 



abdomen, while in the Practical Entomologist, vol. i, p. 249, a figure of the 

 species is given (erroneously referred to the South American B. grandis,) which 

 measures two and one-half inches in length. Another species, the B. ffrisea, 

 occurring in several of the seaboard States, is said to attain the length of three 

 and a half inches. « 



The principal features of this insect — its strong prehensile fore- legs, its flat- 

 tened body, and its broad hind legs, are well shown in the figure. It is an 

 aquatic species, but occasionally takes flight for short distances. Its popular 

 name is the "gigantic water-bug." 



The Belostomae are predaceous, feeding on many of the smaller aquatic in- 

 sects, and on fishes and their eggs. Their presence, therefore, is to be dreaded, 

 in waters devoted to pisciculture. Prof. Glover states (loc. cit., p. 26), that a 

 small goldfish in the aquarium of the Department of Agriculture, at Washing- 

 ton, which had been left over night with a specimen of the B. Americanum, 

 was found the following morning to have been killed by it. 



This species occurs in Texas and throughout the Atlantic region, from Maine 

 to Florida (Uhler). 



NEUROPTERA. 



Perlidce. — One of the two species of Neuroptera, previously referred to, 

 (page 77) as having been captured on the wing at Caledonia, on the first of 

 December, is a species of Leuctra, and, as I am informed by Dr. Hagen, to 

 whom it was submitted, probably undescribed. Of the two known North 

 American species, viz., L. ferruginea and L. tenuis, it is nearer to the latter, 

 and possibly more abundant material (only two examples were taken) and in 

 better condition, might show it to be identical. Dr. Fitch, in his Winter In- 

 sects, (loc. cit.) describes two other species, as Perla nivieola and ISemoura 

 nivalis, which are different from this species. In remarking upon the abun- 

 dance of the two forms, Dr. Fitch says: "One of the purposes served by these 

 prolific insects in the economy of nature, doubtless is, to supply with food the 

 fish of our streams at this early period of the year " (in the latter half of winter, 

 upon the snow). 



Ephemeridce. — The third species captured on the wing (see page 77) was in 

 so broken a condition when received by Dr. Hagen, having lost its legs and 

 other appendages, that it could only be referred with doubt to the genus Baetis, 

 not far from B. alternata Say. It might possibly belong to the genus Pota- 

 wianthus. From its being in the subimago state, determination was rendered 

 more difficult. 



Odonata. — The pupal skin of a large species of dragon-fly was picked up 

 among the dried grasses on the bank of the stream, which Dr. Hagen, from his 

 extensive acquaintance with these forms in their several stages, is able to refer 

 to Anax Junius of Drury. The imago measures four and a half inches in 

 expanse of wings, is of a green color, spotted with blue and fuscous, and with a 

 yellow head. Its larva is correspondingly large and powerful, and from the 

 known habit of most of the Odonata, must be particularly injurious to the cul- 

 ture of fishes. This species has a remarkable distribution, extending across the 

 entire continent from New York to San Francisco, and southwardly into Texas, 

 Mexico and Cuba. It occurs also in the Sandwich Islands, Kamtschatka and 

 China (Hagen). 



In the later February collections, there were contained several living pupae 

 of 2Eschna wrticalis Hagen, shown in figure 10 of plate 5. This is a smaller 

 species than the above, having an expanse of wings of but three and three-fourth 

 inches. Its only assigned habitats are New York State and Washington, D. C. 



