NOTES AND SYNONYMS. 



The long delay in the publication of this number has been occasioned by the 

 protracted illness and final decease of our engraver Mr. Lyon. A young man 

 of amiable manners and much promise in his profession. 



Agreeably to our promise we now give the characters of the genus Cryptos' 

 toma. 



Pecten varius, L. A specimen of this shell was presented to me. several 

 years since by Mr. Lesueur, as having been found by himself on the Northeast- 

 ern coast of the United States. I have not learned that another has been ob* 

 tained on our coast. 



It Been;r<:i)robable that H. irrorata, is a variety of H. lactea, Mull., with 

 which I compared it when describing it. I have a' shell from Rio Janeiro, 

 presented by Mr. T. Peale, that corresponds in all its character with the latter 

 species. Mr. Hyde also sent me the same shells, from near Buenos Ayrcs, so 

 that the lactea, like the aspersa and some of the smaller species, seem* to be 

 very widely distributed. 



Melania semicarinata, Nob. pi. 47, add to the synonyms of this species, M. 

 acuta, Trans. Amer. Philos. Soc. vol. 4, N. S. 



V"alvataj|renifera, Trans. Amer. Philos. Soc. vol. 4, N. S, In the Wissi- 

 hickon ana other streams of water in the vicinity of Philadelphia is the larva 

 of a common insect belonging to the Linnasan genus Phryganea, which con- 

 strud's a spiral follicle precisely similar to the description and figure above re- 

 ferred to, excepting-, of course, that it is destitute of operculum, which the au- 

 thor says, in two of his specimens was " sufficiently perfect to exhibit a stria- 

 ted horny structure." The operculum seems to have been imperfect in both 

 specimens, and we fear that a mistake may have been made, and that the V. 

 arenifera, is in reality only the follicle of a larva and not the production of a 

 moluscous animal. It would be easy to make the necessary comparison, as tb» 

 follicle is well known to most of theconchologists of that city. 

 Caracolla helicoides, ibid, is variety a. of Helix palliata S. H. denotata, per. 

 Helix carolinensis, ibid, corresponds by description and figures with H. ap- 

 pressa, S., var. a. 

 Melania tuberculata, ibid, is a variety of M. stygia, S. 

 Melania elongata, ibid, seem* vf>ry closely related Ko M. elevata, S., find 

 may probably prove to be the same 



COimECTIONS. 



In the note to the observations on the genus Alasmodonta, on the second p«K«, 

 instead of " 1824," read 1B22, and on the cover of No. 3, instead of " 1830," 

 read 1831. 



Plate 53 was inadvertently printed and colored, with Barnes' name Unio 

 nigoBue, instead of Rafinesque's name U. quadrulue, which i» the true name, 

 «r the allsufficicnt reasou that it has the priority. 



