806 CLASS XITI. 



* * Canal elongate ; sinus of labrum not contiguous to canal. Labrum 

 produced into digitate lacinice. Pterocera LAM. 



Sp. Strombus Chiragra L., LISTER Conch. PL 870, fig. 24; Strombus Scor- 

 pius L., D'ARGENV. Conch. PL 14, fig. B, BLAINV. Malac. PI. 25, figs. 3, 

 4, GUERIN Iconogr., Moll. PL 21, fig. 2, &c. 



* * * CtofiaZ short, emarginate or truncated. Sinus of labrum distinct 

 from Canal. Labrum in more adult shells expanded into a wing simple, 

 entire. Strombus LAM. 



Sp. Strombus gigas L., LISTER Conchyl. Tab. 863, fig. 18 ; Strombus latissi- 

 mus L., LISTER Tab. 862, fig. 18 (856, fig. 12 young) ;~Strombus lentigi- 

 nosus L., Cuv. R. Ani., ed. itt., Mott. PI. 61, fig. 2, &c. 



Cassis LAM., Cassidea BRUG. (spec, of Buccinum L.). Shell 

 ventricose or inflated, with spire short. Aperture longitudinal, 

 terminating in a short canal. Columella transversely plicate or 

 rugose. 



a) Canal incurved obliquely to the left and upwards or substraight. Cas- 

 sidaria LAM. 



Sp. Cassis echinophora, Buccinum echinophorum L., RUMPH. Amb. Rariteitlc. 

 Tab. 27, fig. i, GUERIN Iconogr., Moll. PI. 16, fig. 6, &c. The genus 

 Oniscia SOWERBY is distinguished by a short canal and a lamina, covered 

 with granular inequalities, extending from the columella over the last 

 wreath: Cassidaria Oniscus LAM., Strombus Oniscus L., &c. See REEVE 

 Conch. Syst. n. pp. 210212, PI. 253, 254. 



b) Canal ascending, excised deeply towards the extremity. Cassis LAM. 



Sp. Cassis cornuta LAM., Buccinum cornutum L., LISTER Conchyl. Tab. 

 1008; Cassis tuberosa LAM., Buccinum tuberosum L., Encycl. meth., Vers. 

 PI. 406, fig. i, PL 407, fig. 2, BLAINV. Malacol. PL 23, fig. i ; Cassis 

 glauca LAM., Buccinum glaucum L., RUMPH. Amb. Rariteitlc. Tab. 25, figs. 

 A and 4, Cuv. R. Ani., ed. ill., Moll. PL 56, fig. i, &c. 

 Fossil species also of this genus are found. 



Purpura BRUG. Shell oval, often tuberculate, with spire short, 

 last wreath ample. Aperture terminating in a sinus oblique, sub- 

 canaliculate. Columella smooth, acuminate towards the apex. 

 Operculum thin, horny. 



DUCLOS (Ann. des Sc. nat. xxv. 1832, pp. 9095, xxvi. pp. 103 112), 

 DESHAYES (Encycl. meth., Vers. in. pp. 838 845) and BLAINVILLE (Nouv. 

 Ann. du Mus. i. pp. 189 263) have united under the name of Purpura, 

 besides Monoceros and Ricinula of LAMARCK, also Concholepas LAM. ; they 

 regard these genera merely as divisions of a great genus, to which more 

 than 200 species now belong. 



Ricinula LAM. Aperture oblong, narrowed by unequal teeth at 

 the columella and the internal surface of labrum. Shell often tu- 

 berculato-spinose. 



