DENTALIUM-EPISIPHON. 119 



p. 148-. BALL, Blake Rep. Bull. M. C. Z., xviii, p. 419 (1889); 

 Bull. 37, U. S. Nat. Mus., p. 76 ; Trans. Wagner Inst., iii, p. 441 

 (1892). Z). graeile JEFFREYS, Ann. Mag. N. H. (4), vi, p. 74 

 (July, 1870), and (5), vi, p. 317 (1880). Not of Meek. FISCHER, 

 Journ. de Conchyl., 1872, p. 140, pi. 5, f. 5. D. rnfescens (in part) 

 WEINKAUFF, Conch, des Mitteim., ii, p. 420. 



Fully mature shells are nearly cylindrical, the truncated and 

 often tubiferous apex almost as wide as the larger end ; the young 

 are acicular, tapering. Color either white or faintly fulvous. Jef- 

 freys writes : "Mr. McAndrew tells me that the animal was of a 

 greenish color. Not the young of D. rubeseens. The present spe- 

 cies is more regularly cylindrical, narrower and nearly equal in 

 breadth throughout. It is curved, which shows that it is adult, the 

 very young of all species of Dentalium being almost straight." 



D. INNUMERABLE Pilsbry & Sharp, n. sp. PI. 18, figs. 6, 7, 8. 



Shell small, but slightly curved, excessively slender, and in adults 

 only slightly tapering ; thin and fragile, glossy, the smoothies* of 

 the polished surface scarcely interrupted by delicate faint growth 

 strict; no other sculpture. Flesh or salmon colored, fading into 

 translucent white near the aperture, and often with some oblique 

 white rings at irregular intervals. Aperture oval, the tube being 

 compressed laterally. Anal orifice circular, occupying a small and 

 short projecting pipe in most adults, but this is very short or want- 

 ing in some examples. Length 17, antero-posterior diam. of aper- 

 ture 0'8, lateral diam. 0*7 mill. ; diam. at apex 0'6 mill. 



Panama Bay in 26, 29* and 51 frns. ; off Guaymas in 20 fms. ; 

 off Lower California near Sta. Margarita Island, lat. 24 32', long. 

 111 59' in 12 fms. ; and near Cerros /., lat. 28 12', long. 115 9', 

 in 44 fms. (U. S. Fish Commission Str. * Albatross'). 



Like D. sowerbyi, filum and fistula, but the tube is distinctly, 

 though not much, compressed from side to side. It occurred in great 

 numbers in the Bay of Panama. D. ottoi Sharp & Pilsbry (D. 

 compressum O. Meyer, not Orbigny), is evidently a closely allied 

 species from the Oligocene of Joachimsthal, Germany. Immature 

 shells are more tapering, being smaller toward the apex, as usual. 



D. SUBRECTUM Jeffreys. PI. 18, fig. 5. 



Shell acicular or needle-shaped, thin, extremely slender, tapering 

 almost to a point, nearly straight, translucent whitish, with the 

 faintest reddish tint from the middle to the apex. Surface very 



