654 EEPORT OF COMMISSIONER OF FISH AND FISHERIES. 



Eissoa ACULEUS Stimpson. Plate XXIY, fig. 141. (p. 306.) 



Proc. Boston Soc. Nat. Hist., vol. iv, p. 15, 1851 ; Shells of New England, p. 

 34 ; Gould, Invert., ed. ii, p. 299, fig. 563. Cingula aculeus Gould, Invert., ed. 

 i, p. 286, fig. 172, 1841. Trochus striatellus Kabricius, Fauna Gronl., p. 393, (non 

 Liune). (f)Bissoa saxatilis Moller, Index Mollusca Gronl., in Kroyer's Tids- 

 skrift, vol. iv, p. 82, 1843. (f)Eissoa arctica Love"n, Ofversigt af Kongl., Vet.- 

 Akad. Forhandlingar, vol. iii, p. 156, 1846. 



Long Island Sound to Greenland. New Haven, Connecticut, and vicin- 

 ity, common. Watch Hill, Bhode Island ; Vineyard Sound ; Stratford, 

 Connecticut (Linsley); Gull Island (Smith). Common on the shores 

 of Massachusetts Bay, Casco Bay, and Bay of Fundy. 



Lov6n's B. arctica was from Fininark, and, to judge from the de- 

 scriptions, may not be identical with our species. Mr. Jeffreys regards 

 it as a variety of B. striata of Europe. He also unites the American 

 shell with B. striata, thus : " The variety arctica (under the specific 

 name aculeus given to it by Professor Stimpson) inhabits the northern 

 sea-board of the United States." (See British Conchology, vol. iv, p. 38). 

 It is natural to infer that a writer who does not appear to have seen 

 the accurate description and figure of this species published in the 

 well-known work of Dr. Gould, ten years previous to Dr. Stimpsou's 

 earliest publications, cannot have devoted much time or attention to 

 the American shells, and therefore his opinions should not have too 

 much weight in such cases. 



In reality, our shell differs widely from B. striata. It agrees more 

 nearly with the English B. proxima (Alder, Forbes and Hanley), but 

 apparently differs from it in the soft parts. The foot in our shell is 

 broadly and slightly rounded anteriorly, with the angles only slightly 

 produced, and tapers backward to a bluntly-rounded posterior end. 

 The tentacles are long, slender, slightly tapering, with blunt tips. The 

 eyes are situated near their bases on the dorsolateral aspect, and are 

 scarcely elevated above the general surface. The snout is rather long, 

 often a little expanded at the end, and divided by a deep emargination 

 into two lobes, which often, in a dorsal view, show a slight emargina- 

 tion on their outer surface. No opercular cirrus was observed. This 

 species belongs to the genus Onoba of H. and A. Adams. The B. 

 saxatilis was described by Moller as having the whorls smooth, but he 

 refers to T. striatellus of Fabricius, which had spiral striations, as in our 

 species. 



Eissoa exarata Stimpson. (p. 495.) 



Proceedings Boston Soc. Nat. Hist., vol. iv, p. 15, 1851; Shells of New England, 

 p. 34, Plate 1, fig. 3, 1851 ; Gould, Invert., ed. ii, p. 301, fig. 571. Cingula 

 arenaria Mighels and Adams, Boston Jour. Nat. Hist., vol. iv, p. 49, Plate 4, 

 fig. 24, 1842 (wow Montagu, sp.). Eissoa Mi ghelsii Stimpson, Proc. Bost. Soc. 

 Nat. Hist., vol. iv, p. 15, 1851 ; Shells of New England, p. 34 ; Gould, Invert., 

 ed. ii, p. 301, (but not figure 570, which is probably E. sulcosa). 



Stoningtou, Connecticut, to Gulf of Saint Lawrence. Watch Hill, Bhode 

 Island, 4 to 5 fathoms, among rocks and alga3 (white variety) ; Casco Bay, 



