ADDITIONS-RECENT SPECIES. 249 



D. eoiispicuum Melv., Mem. and Proc. Manchester Lit. and 

 Philos. Soc, xli, pt. 3, 1896-97, p. 21, pi. 7, f. 28 (1897). 



A milk-white, conspicuous species, slightly arcuate, eight-angled 

 at the apex, the longitudinal strise very unequal down the body of 

 the shell, and entirely vanishing before the base, which is very 

 smooth and round at the orifice. It is concentrically unequally 

 lirate ; two specimens (Melv.). 



D. coNciNNUM von Martens. 



Shell weakly curved, with distinctly defined but not sharp longi- 

 tudinal ribs, at the apical end 12 in number, increasing anteriorly 

 by intercalation to more than double that number, separated from 

 «ach other by about double the breadth of the ribs ; becoming weaker 

 anteriorly, and with fine, crowded circular lines equally developed 

 upon ribs and interstices ; white, somewhat shining. Apex without 

 slit, thick-margined, with 12 small notches outside. Aperture some- 

 what elliptical and oblique to the axis. Length of chord 44, of arc 

 46 mill. ; longer diameter of aperture 4, shorter 3? mill. ; diameter 

 of the apex 1 mill. (Martens). 



West Coast of Africa, N. lat. 10' 6' 9", W. Ion. 17° 16' in 150 fms. 

 (Gazelle Exped.). 



D. concinnum Martens, Sitzungs-Bericht Ges. Naturforscheuder 

 Freunde zu Berlin, meeting of June 18, 1878, p. 134. 



Evidently a member of the group of D. agassizi (p. 26), and to 

 be placed near D. shoplandi. 



D. QUADRAPicALE Sowerby (p. .34). 



Reported by Mr. E. A. Smith from off the coast of Travancore, 

 South India, in 406 fms., dredged by the ' Investigator ' (Ann. Mag. 

 N. H., xviii, p. 371, November, 1897). The specimens are some- 

 what larger than that figured by Sowerby, the largest having a 

 length of 40 mill. 



A section of Dentalium, Tesseracme, may advantageously be 

 erected for the forms included in the " group of D. quadrajncale," 

 p. 31. 



D. pretiosum ' Nutt.,' Sowerby (p. 44). 



Carpenter says somewhat enigmatically that the I), pretiosum of 

 the Mazatlan Catalogue is probably D. ladeum Phil. AVe know of 

 no such species. See Rep. Brit. Asso. Adv. Sci., 1863, pp. 545, 

 •666, and Moll. Western N. A., pp. 31, 152. 



