CHEMNITZIA. 425 



very slender varieties, one of which is figured in the ' British 

 Mollusca/ under the appellation of C. formosa, which most 

 accurately represents our true Exmouth shells of the ' ' rufa," 

 in which, in perfect specimens, there are often fourteen volu- 

 tions and twenty ribs on the body ; they are plain, straight, 

 and not raised ; the suture, instead of a fine line, is decidedly 

 grooved ; the interstitial striae are adequately developed ; the 

 basal periphery of the aperture is usually less rounded and 

 more subquadrangular, and the base of the body-whorl exhi- 

 bits greater tumidity than in the C. fulvocincta. Our beautiful 

 and perfect specimens are not glabrous ; on the contrary, they 

 show a palish dull rufous colour, with not a trace of the con- 

 spicuous tawny-orange spiral fascia of its congener : in fact, 

 the true " rufa" differs in every point from the "fulvocincta" 

 This comparison obliges me, with every deference, to submit, 

 that for the Chemnitzia rufa of the authors of the ' British 

 Mollusca/ the C. fulvocincta be substituted, and the southern 

 shell they have alluded to, be named C. rufa, as it and the 

 Exmouth examples truly represent that species; of which 

 their C. formosa is a slender variety and synonym ; indeed 

 its figure excellently represents the " rufa" 



The C. rufescens is decidedly distinct from either the 

 ' ' rufa " or "fulvocincta" 



CH. FULVOCINCTA, Thompson and Alder. 



Ch. fulvocincta, Brit. Moll. iv. p. 276, pi. 93. f. 4 (not fig. 3) ; (animal) 

 pi. F.F. f. 4, as rufa. 



See the notes above for what is known of this species. 



CH. SPIRALIS, Mont. 



Odostomia spiralis, Brit. Moll. iii. p. 299, pi. 97. f. 2; (animal) pl.F. F. 



f. 8, 9. 

 Turbo spiralis, Mont. 



Animal occupying a spiral shell of four flat volutions. 

 Mantle even. The colour in all parts is hyaline- white, deli- 

 cately suffused with snow-white points of several magnitudes. 

 The rostrum is moderately long, entire, flat, plain, rounded in 



