12 CONCHOLOGY. 



FAMILY II. 



MALDANiiE. Two genera. 



1. Clymene. One species. 



C. amphistoma. The double-mouthed Clymene. 

 Tube thin and slender, open at both ends ; incrusted ex- 

 ternally with sand and fragments of shells, 



2. Dentalium. The Tooth Shell. Twelve species. 



This genus took its name from its resemblance to an ele- 

 phant's tooth. It is an attenuated conical tube, slightly bent, 

 and open at both ends. 



Shell tubular, regular, symmetrical, lightly curved longi- 

 tudinally, conic, attenuated insensibly posteriorly, and open 

 at each extremity by a round orifice. 



Dentalium elephantinum. Dentalium octoganum. 



D. aprinum. D. novemcostatum. 



D. fasciatum. D. dentale. 



D. entale. D. nigrum. '} 



D. Tarentinum. D. politum. 



D. corneum. D. eburneum. 



D. elephantinum, The Elephant's Tooth Shell. 

 Species in which the tube is striated or ribbed longitudi- 

 nally ; the ribs are generally ten in number ; green colour. 



D. entale. The common Dentalium. PI. 33, fig. 1. 

 Species very minutely striated ; white or yellowish colour. 



p. pellucidum. The pellucid Dentalium. 

 Species narrow and thin ; pale topaz colour. 



D. politum. The ring-striated Tooth Shell. 

 Species finely pointed, solid, striated annularly ; generally 

 rosy or pink colour. 



D. rectum. The straight Tooth Shell. 

 Species entirely straight, with longitudinal ribs. 



