DENTALIUM-ANTALIS. 47 



out of the larger and longer one, as if from a sheath. This process 

 has an entire and circular point; so that the shell cannot be a 

 species of Siphodentalium. Length 12*5 mill. (7e$r.). 



N. Atlantic, Station 16, 1785 fms. (Valorous Exped.). 



D. vagina JEFFR., Ann. Mag. N. Hist. (4), xix, (1877), p. 155 

 (concealed in text relating to D. subterfissum). 



Described from a dead specimen, which Jeffreys was apparently 

 ashamed to formally introduce as a new species. It is a wretched 

 fragment of a young shell, which owes the projecting tube to loss 

 of the outer shell layer, as described under D. agassizi, not to inde- 

 pendent growth as in D.filum, innumerabilis, and the vulgare group. 

 After examining the type and another specimen, we have no hesita- 

 tion in declaring it a young D. agile. At all events, its absolute 

 counterpart can be found in the long-dead young of this species. 

 The figure is an enlarged drawing of the type. 



D. OCCIDENTALS Stimpson. PI. 13, figs. 9, 10, 11 ; pi. 9, figs. 41, 42, 

 43 (young). 



Shell moderately curved, the bend mainly posterior, rather solid, 

 lusterless ; whitish, frequently tinted with yellow or fleshy. Sculpt- 

 ure of about 12 rather strong ribs toward the apex, gradually be- 

 coming lower and wider anteriorly, and increased to double that 

 number by the intercalation of as many intermediate riblets, all of 

 which become subobsolete toward the aperture, which is oblique and 

 circular. Anal orifice circular not notched or slit, or with a short 

 slit on the convex side. 



Length 34, diam. of aperture 3*9, of apex 1 mill. 



North Atlantic, from off New England north to Newfoundland; 

 Spitzbergen, Norway and Faroe Is. (According to Jeffreys south to 

 Bay of Biscay and Azores). 



D. occidentale STIMPSON, Shells of New England, p. 28 (1851) ; 

 no description, being based on D. dentale Gould, Invert. Mass., p. 

 155, pi. 1, f. 5. D. occidentale VERRILL, Trans. Conn. Acad., v, pi. 

 42, f. 16-18; Rep. Commissioner Fish and Fisheries for 1883, p. 

 573, pi. 28, f. 123-125. WHITEAVES, Rep. on a Second Deep-sea 

 Dredgiug Exped to the Gulf of St. Lawrence, etc., p. 17 (1873). 

 D. dentale GLD. in Invert. Mass.,- edit. W. G. Binney, p. 266. D. 

 abyssorum SARS, see below. 



This shell has curiously enough been mistaken for D. striolatum 

 Stimpson, by Jeffreys (P. Z. S., 1882, p. 659), Watson (Chall. Gastr., 



