Mgures. 



Cymbium LiNNiEi. (Voluta cymbium, Linn). Plate 2. Fig. 8. — Shell, 

 showing the papillary spire, and the summit of the whorls flattened. 



Cymbium Beoderipii. Plate 2. Pig. 10. — Shell, showing the papillary 

 spire, and the summit of the whorls coronated with vaulted scales. 



Genus 2. VOLUTA, Linnceus. 



Animal ; disc oval or ohlong, head obtuse or romided, tentacles 

 short, eyes a little removed from the tentacles; respiratory 

 siphen stout, auriform, dilated at the base into two lobes. 



Shell ; ovate or oblong, emarginated at the base, spire short and 

 mostly papillary at the apeoc ; tuhorls smooth or ribbed, some- 

 times tuberculated at the summit ; aperture oblong, columella 

 callous, lower plaits the larger ; lip but slightly thickened. 



Linnseus included under the head of Voluta all shells having a row of 

 plaits winding round the columella, without considering the nature or 

 habits of their animal occupants ; the Tornatella, whose shells are entire 

 at the base, the Anrimlce, wliich inhabit the banks of stagnant waters and 

 are amphibious, the TurUnellm, which are canaliculated, and the Margi- 

 nell(E, in which the shell is entirely enveloped by the animal, were all asso- 

 ciated in the ' Systema Naturae ' under the same generic type. Tliis hete- 

 rogeneous group has, however, been gradually dismembered, until only 

 those species remain wliich present the characters strictly typified in the 

 well-known V. scaplia, nmsica, or vespertilio. The ancient genus Voluta 

 is, therefore, circumscribed within very narrow hmits, and some of the 

 species are of such rare occurrence, that only a few individuals of the shells 

 of each have yet been discovered; the V. Jimonia, aulica, reticulata, 

 megaspira, papillosa, Mitraformis, pidchra, and marmorata are examples. 



The animal of Voluta scarcely differs from that of Cymbium except in being 

 smaller, less expansile, and more brilliantly coloured ; it presents the same 

 peculiar lobed dilation of the respiratory siphon, and the eyes, as in that 

 genus, are quite removed from the tentacles. The species hitherto dis- 

 covered in a living state, exliibit as brilliant a variation of colour in the soft 

 parts as in the shell. The V. vespertilio is characterized by a bright yeUow 

 disc, marked with longitudinal interrupted black Hues, the V. angulata, by 

 a rusty orange tint, marked tlu-oughout with dark leopard spots, the V, 

 nivosa, purple, marked with unequal black spots with white edges, and the 



