SHELLS. 



Specimens of this species were dredged from a depth of 

 seventy-four fathoms. 



N. sulcifera (PI. XXXIII. Fig. 1 a , b, c). Nuc. testa sub- 

 anguste-ovata, cornpressa, ad umbones gibbosiuscula, subaequi- 

 laterali, latere postico rotundatOj antico leviter concavo-flexuoso 

 et obtuse rostrato, valvis concentrice superficialiter sulcatis, 

 sulcis distantibus ; albida, epidermide virente cornea induta. 



A narrow,, ovate, flexuously-beaked species, marked with 

 concentric, superficial, widely-separated grooves. 



N. expansa (PL XXXIII. Fig. 2 a, b) . Nuc. testa sub- 

 trigono-ovata, vix ventricosa, subcompressa, latere antico 

 brevissimo, truncate, vix nullo, postico rotundato, expanso- 

 producto ; alba, epidermide cornea cinereo-virente iiitente 

 induta. 



Allied to N. inflata, Hancock, but more compressed and 

 more expandedly produced posteriorly. 



Hob. Northumberland Sound and Port Refuge. 



N. sapotilla, Gould, Invert. Mass. p. 100. f. 61. 



LEDA (Schumacher). 



L. buccata, Steenstrup, Moller, Ind. Moll. Grcenlandiae, 

 p. 17. 



MODIOLA (Lamarck). 



M. marmorata, Forbes (Modiola), Malacologia Monensis, 

 p. 44. 



M. tumida, Hanley. 

 M. Poliana, Philippi. 



M. Icevigata, Gray, Appendix, Parry's Voy. to North Pole, 

 p. 245. 



M. nigra, Gray, Appendix, Parry's Voy. to North Pole, 

 p. 245. 



M. depressa, Hanley. 



ASTARTE (Sowerby). 

 A. Richardsoni (PI. XXXIII. Fig. 7 a, b}. Ast. testa sub- 



