144 Note on Certain Insect Larva-Sacs. 



received, which is of especial interest, it being the first of the 

 genus that has been noticed as found in American waters. It 

 belongs to Callionymus as restricted by myself, but is distin- 

 guished by the small number of dorsal and anal rays (D. III. 

 6, A. 4.) The preopercular spine is armed with three teeth 

 above and terminates behind in an acute point. The species 

 may be named Callionymus pauciradiatus. 



ILYI.—Note on Certain Insect Larva-Sacs, described as Species 

 of Yalvat^e. 



By Thomas Bland. 

 Bead April 3d, 1S65. 



Some years ago I collected in the Island of Jamaica, W. I., 

 from a stream of fresh water, small objects like spiral univalve 

 shells, which I supposed to be mollusks, but after examination 

 and inquiry discovered my error. 



Subsequently I learned that an object of similar character 

 had' been described by Mr. Isaac Lea as Valvata arenifera, 

 which proved, however, to be the case of the larva of a Phry- 

 ganidous insect. At a later period specimens, not unlike those 

 noticed in Jamaica, were sent to me from Canada West, under 

 the name of Thelidomus Braziliensis Swainson. 



De Kay {Nat. Hist, of New York, Mollusca, p. 119), with 

 his description of Valvata sincera Say, has the following obser- 

 vation : — 



"There is frequently found associated with this and the preceding 

 species (V. unicarinata) an agglutinated arenaceous mass, resembling 

 them very much in form. This has been described as V. arenifera in 

 the Transactions of the American Philosophical Society (vol. 4, p. 104, 

 pi. 15, fig. 36. A. B), and has since been erected by Mr. Swainson into 

 the new genus Thelidomus (see Lardner's Cabinet Cyclopaedia, No. 123, 

 pp. 226, 353). It is believed to be the case of the larva of some aqua- 

 tic insect, possibly a Phryganea." 



