Note on Certain Insect Larva-Sacs. 145 



In the summer of 1862, I received from Mr. Henry Rousseau 

 a number of these larva-cases, collected \j him in the vicinity 

 of Troy, N. Y. The specimens were in alcohol, but at my 

 request Mr. Rousseau sent to me living ones, which I placed in 

 a small aquarium, wishing to observe their habits and destiny. 

 During the following autumn and winter the larvae were 

 extremely active, creeping about on the stones and feeding 

 apparently on confervse. If disturbed, the larva withdrew into 

 its abode, which then seemed to be" somewhat firmly fastened 

 or secured to the object on which the case happened to rest. 



Early in the spring of 1863, I noticed what appeared to be 

 the exuviae of the nympha of an insect floating on the surface 

 of the water in the aquarium, and empty larva-cases at the 

 bottom. Suspecting that some of the insects had flown, I 

 placed a gauze net over the aquarium, and in a few days 

 obtained several perfect imagines. Believing that these would 

 be very interesting to naturalists, I consulted Mr. Akhur'st, 

 and at his suggestion forwarded the insects and cases to Mr. 

 P. R. Uhler, who reported that they probably belonged to the 

 genus Jlelicopsyche of the family Hydropsy 'chidce, and that the 

 species was perhaps new. He sent the specimens to Europe 

 for determination by Dr. Hagen, but I have not at present 

 heard the result. 



• In a paper entitled " Descriptions of New Species of Fluvia- 

 tile and Terrestrial Operculate Mollusca from Trinidad" (Ann. 

 and Mag. of Nat. Hist, JNo. 82, Oct., 1864) by Mr. R. J. 

 Lechmere Guppy, is the following description, evidently of a 

 Jlelicopsyche-s&c, but treated by the author as a Valvata. 



"Valvata agglutinans. — Shell trochiforrn-depressed, perforate, entirely 

 composed of numerous minute grains of mineral matter ; whorls 3-4, 

 almost carinate, flattened beneath ; umbilicus circular ; aperture very 

 oblique, circular, the margins shortly united on the penultimate whorl ; 

 peristome simple, irregular. Height 0.1 inch, greatest breadth 0.17 inch. 



"It lives on the surface of rocks and stones in the hill streams of the 

 northern part of Trinidad." 



