CO^CHYLW—DITHYRA. 24. 79 



^ Valvis unideniatis. 1-2. 

 With a single tooth in each valve. 



SoLEN testa, rectd, extremilate anticd constrictn-marginatd, v»giu». 



dentibus complanato-rotundatis. 

 Shell straight, margined by a stricture at the anterior end, with 

 the teeth flat and rounded. 



Tab. nost. 6, fig. 4. 

 Solen Vagina. Linn. Syst. Nat. p. 1113. 



Gmelin, Syst. p. 3223. 



Ttirton, Linn. Syst. iv. p. 180. 



Pennant, iv. p. 171. tab. 49, fig. 1. 



Chemnitz, vi. p. 40, tab. 4, fig 26, 27. 



Montagu, p. 48 and 565, and Suppl. p. 25. 



Linn. 2rans. viii. p. 42. 



Turton, British Fauna, p. 148. 



Dorset Catal. p. 28, tab. 4, fig. 8. 



Wood, Conch, p. 119, tab. 27, fig. 1. 



Dillwtjn, Descript. Catal. p. 57. 



Tui'tun, Conch. Diet. p. 159. 

 Solen raarginatus. Donovan, British Shells, iv. tab. 110. 

 Solen rectus brevior. Listen, tab. 410, and 1056, fig. 5. 

 Mus. nost. Western and Irish coasts. 



Shell hardly an incli long, and four or five broad, of a nearly 

 cylindrical form, covered with a yellowish skin which extends 

 nearly an inch beyond tiie hinder end, not divided diagonally like 

 most of the species: at the hinge end is a strong indenture or 

 ligature, and a thickened rib-like elevation on the inside. 



