SMITH : ox THE GENUS ASTARTE. 2 1 3 



respecting the propriety of separating the A. lens, but I fail to 

 find any sufficient differences in the description given by Gould. 



6.— ASTARTE CRENATA Gray. 

 1824. Nicania crenata Gray. Parry's First Voy. Apend., 



p. ccxlii. ; Zool. Jour., vol. i., p. 119. 

 1843. Crassina crenata Hanley. Cat. Rec. Biv., p. 88. 

 1854. Astarte obionga Sowerby. Thes. Con., vol. ii., p. 781, 



pi. clxvii., f. 19. 

 1872. A. obionga Tryon. Proc. Acad. Nat. Sci. Philad.,p. 247. 

 1874. A. crenata Sowerby. Con. Icon., vol. xix., f. ga — b. 



Habitat. — Prince Regent's inlet, north of British North 

 America (Capt. Sir E. Parry, R.N.) 



This species may be distinguished from crebricostata by its 

 smaller size and the very much finer concentric riblets which 

 extend from the anterior end over about two thirds of the surface 

 of the valves, leaving the hinder portion merely finely striated. The 

 form too, judging from the fourteen specimens in the museum, 

 is more elongate transversely and appears to be constant in this 

 respect. The inner edge of the valves as in the other species of 

 the genus which have crenulated margins, only become denticulate 

 when maturity is reached. 



7.— ASTARTE ACUTICOSTATA Jeffreys & Friele. 



1876. A. acuticostata J. & F. Nyt Magazin for Naturvidens- 



kaberne, vol. xxiii., part 3. 



1877. A. acuticostata Kobelt. Jahrbuch. Deutsch. Mai. 



Gesell., vol. iv., p. 257. 

 1879. A. acuticostata Friele. Jahrbuch. Deutsch. Mai. 



Gesell., vol. vi., p. 267, pi. iv., f. 8. 

 1881. A. acuticostata Jeffreys. P. Z. S., p. 711, pi. ixi., f. 9. 

 Habitat. — North Atlantic, in the cold zone at various 

 depths of 290, 418, 488 and 510 fathoms; also betAveen Scotland 

 and the Faroe Islands, and Nova Zembla. 



