Mr. E. A. Smith on Arctic Mollusca. 145 



tion — the former being " fine, close, regular," and the latter 

 pale greenish yellow. These shells, in shape, can certainly 

 be matched with some specimens of A. striata^ and do not 

 appear to vary in any thing except the difference of colour of 

 the epidermis, which in the latter species is brown or olive- 

 brown. This species is considered the same as A.fahula by 

 Jeffreys. 



My a truncata, Linn., 



Forbes and Hanley, Brit. Moll. pi. x. f. 1—3 ; Jeifrevs, Brit. Conch, iii. 



pi. 3. f. 1, vol. V. pi. 50. f. 2 ; Gould, Invert. Mass. ed. 2, f. 376 ; 



for list of other figiu-es see Gray's Cat. Brit. Moll. 1851, p. 68. 

 Var. pelagica, King, Ann. & Mag. Nat. Hist. 1846, xviii. p. 242. 

 Junior=ilf. ovalis, Tui-ton, Brit. Biv. pi. 3. f. 1, 2. 



= Sph(Bma Sioamsunii, Tiirton, Brit. Biv. pi. 19. f. 2. 

 'Va.r. = Ml/a tiddevalensis, Forbes, Hancock, Ann. & Mag. Nat. Hist. 



1846, xviii. p. 337. 

 M. prceckn, Gould, Proc. Bost. Soc. Nat. Hist. 1850, vol. iii. p. 215 ; 



Atlas, Wilkes Explor. Exped. pi. 33. f. 498 a, b. 



Hah, Discovery Bay, 5 and 25 fms. [Hart and Feilden) ; 

 Dobbin Bay, 30 fms. {tiart). 



All the specimens from these localities have the posterior 

 marginal slopes directed inwards or towards the base of the 

 shell, which peculiarity is characteristic of the variety ud- 

 devalensis. One shell is remarkable on account of the abrupt- 

 ness of the truncation and its narrowness, the width being only 

 6 millims. more than the length (30 millims.). 



Saxicava arctica^ Linn. 



For the synonvma of this species see Brit. Mus. Cat. Brit, Anim. part 

 vii. pp. '^86-89. 



Hah. Discovery Bay, 5 fms. [Feilden] ; Franklin-Pierce 

 Bay [Hart and Feilden) ; Dobbin Bay, 30 fms. [Hart). 



Some specimens from Franklin-Pierce Bay are remarkable 

 on account of their great solidity, the depth and distinctness 

 of the muscular scars, and the purplish brown colour which 

 stains both the inside and exterior of the valves. 



Mr. Hart found dead examples at Cape Frazer at an eleva- 

 tion oC 10 feet above sea-level. 



Modiolaria Iwvigata, Gray. 



Modiola laviffata, Gray, Appendix Parry's Voy. 1821, p. 245 ; Reeve, 



Conch. Icon. x. sp. 53, f. 66. 

 Mytilus Iceviguttis, Wood, Index Test. Suppl. pi. 2. f. 5. 

 Modiolaria discors, Gould (non Linn.), Invert. Mass. ed. 2, 1870, p. 192, 



fig. 489 (var. l<svif/ata). 



Hah. Franklin-Pierce Bay, 15 fms. [Feilden and Hart). 

 Ann. & Mag. N. Hist. Ser. 4. Vol. xx. 10 



