62 Lamarck's Genera of Shells. 



Type. Mitra episcopalis*. (Volutaepiscopalls. Linn.) 

 Shell turrited, smooth, white, spotted with red ; the lower spots 

 square, disposed in regular order, transversely ; the upper irre- 

 gular; superior margin of the whorls entire ; columella quadripli- 

 cate, lip toothed posteriorly. Indian Ocean. El, v. Fig. 199. 

 80 Recent species, and 14 fossil. 



3. Volutaf. 

 Shell oval, more or less ventricose ; summit obtuse, or mamel- 

 lated; base notched; no canal. Columella plaited; lower plaits 

 largest, and most oblique. No columellar lip. 



Bruguieres began the reform of the too numerous genus voluta, 

 as established by Linneus, by removing from it all the shells which 

 have no notch at the base. Lamarck has carried it still further, 

 by separating from it the mime, columbellfe, marginellse,cancellarise 

 and turbinellse. The genus still contains a great number of spe- 

 cies, many of which are remarkable for the variety, beauty, and vi- 

 vacity of their colours. They are generally smooth and brilliant, 

 and do not appear ever to be covered with an epidermis. Some of 

 them are very ventricose, others simply oval, and covered with tu- 

 bercles; others again are ovate-conical, elongated, almost fusiform, 

 or turrited, and approach the shape of the mitree. They are all 

 marine shells, and generally inhabit the seas of hot climates. No 

 species of this genus is found in our seas. 



The voluta? are distinguished from the mitrse by the lower plaits 

 on the columella being larger than the upper, and by the obtuse 

 and mammellated termination of the spire. 



Lamarck separates them into four subdivisions, viz. — 1 . cymbiolce, 

 ventricose shells. 2. Muricince, oval, spinous, or tubercular. 

 3. Musicales, oval, subtubercular. 4. Fusoidece, elongated, ventri- 

 cose, subfusiform. 



Type. Voluta Diadema\. (Voluta cethiopica-var. Linn.) 

 Shell ventricose, orange yellow, sometimes marked with white ; 



* Episcopal. t Volute. 



$ Diadem. Lamarck's second species of the first subdivision. His type is 

 V. nauticu. 



