INSTITUTE OF SCIENCE, PHILADELPHIA. 44I 



Dentalium filum Sowerby. 



D filum Sby.,Thes. Conch., p. 99, pi. 225, fig. 45, iS56 ; Jeffreys, P. Z S. 18S2, p. 60 ; Dall, 



Blake Gastr., p. 419, 18S9. 

 D. gracile Jeffreys, Ann. Mag. N. Hist., July, 1870 ; not of Meek. 



Older Miocene of the Chipola beds, Calhoun Co., Florida, Burns ; Pliocene 

 of Calabria, Seguenza ; living in the North Atlantic and Mediterranean in 20 to 

 1093 fathoms, and off the coast of North Carolina at various stations of the 

 U. S. Fish Commission in 17 to 124 fathoms. 



This elegant little shell is easily recognized by the regular annulations by 

 which it is sculptured, and its straight and slender form. It has an enormous 

 range both in space and time. 



Dentalium agile Sars var. oleacinum. Dall. 



D. agile M. Sars, Dall, Blake Gastr., p. 418, 18S9. 



Antalii agilis G. O. Sars, Moll. Reg. Arct. Norv., p. 102, pi. x.x. fig. 9, 1878. 



Pliocene of the Caloosahatchie and Shell Creek (rare), Dall and Willcox ; 

 living in the North Atlantic from Norway to the Straits of Florida in deep 

 water. 



The specimens appear to agree in form, shape, size, etc., with authentic 

 specimens of D. agile, except that while agile proper has a smooth surface, the 

 present form has the exterior polished. Without more material the perma- 

 nency and value of this character cannot be determined, but should it prove to 

 be specifically different, the varietal name now given may be raised to specific 

 rank. 



Dentalium caloosaense n. s. 

 Plate 23, figure 24. 



Pliocene of the Caloosahatchie and Shell Creek, Florida, Dall and Will- 

 cox. 



Shell slender, solid, not polished, moderately curved, the orifices circular; 

 sculpture begins at the small end, which is a rectangular prism with equal flat 

 sides and the angles dorsal, ventral and lateral, with, occasionally, in truncate 

 specimens, a short, smooth circular supplementary tube projecting from the 

 truncate surface ; the four angles soon become four flat-topped, square-sided, 

 prominent ribs, between which four more, and then eight more, smaller but 

 similar ribs appear by intercalation ; these ribs become obsolete about the 

 anterior third of the adult shell, beyond which the surface is marked only by 

 concentric incremental lines. Lon. of adult 50.0 ; ant. diam. 4.5 ; post. diam. 

 i.O ; perpendicular of the dorsal arch 7.5 mm. 



This species recalls tlialloide , attenuatuvi, the recent Gouldii and dentalis, 

 but agrees in its combination of characters with none of them. It is, perhaps, 

 nearest D. Gouldii Dall, which is a proportionally longer and more slender 

 shell living in 12 to 150 fathoms .from South Carolina to Barbados. 



