43 



Fiffures. 



Cype^a TIGRIS. Plate B. Fig. 3. — Shell with the animal, showing its ex- 

 panded green-spotted disk, cyhndrical head surmounted by the fringed 

 fan-shaped siphonal appendage, tentacles and prominent eyes, and left 

 lobe of the mantle with its forked processes, partially expanded over 

 the shell. From the Zoology of the Voyage cle V Astrolabe. 



Cypr^a leucostoma. Plate. 2. Fig. 9, a and h. — Shell, showing, a, 

 the dorsal, h, the under surface. From Mr. Cuming's ccftkction. 



Genus 5. ERATO, Risso. 



Animal ; similar to the Ci/praa, with the lobes of the mantle very 

 thin and speckled. 



Shell ; small, ovately ohlong, smooth, emarginated at the base, 

 spire rather prominent, last whorl a little inflated ; aperture 

 narrow, lip and columella more or less finely denticulated, lip 

 thickened, generally sivollen toioards the middle. 



The genus Frato was originally founded by M. Eisso, a distinguished 

 conchologist of Nice, with a small shell, chiefly inhabiting the Mediterranean, 

 intermediate in its characters between Cypraa and Marginella, and 

 forming a striking link between the families Columellata and Convoluta. 

 It has the form and general aspect of Marginella, but the most important 

 distinguishing character of that genus, the row of plaits which twine 

 around the columella tlu"ough the entire growth of the shell, is replaced by 

 a minute series of denticulations, which only make their appearance on its 

 arriving at maturity ; and it is not surprising, therefore, under these cir- 

 cumstances, that one Linnsean author, Montagu, should have regarded the 

 F. Imvis as a Voluta, whilst another, Donovan, should have referred it to 

 the genus Cypraa. Seven other interesting species have since been added. 



Species. 



1. angistoma, Sow. 4. Isevis, Gray. 7. sidcifera, Gray. 



2. guttata, Sow. 5. Maugeriae, Gray. 8. vitellinum, Hinds. 



3. lachryma, Gray. 6. scabriuscula. Gray. 



Figure. 

 Erato L^vis. Plate 1. Pig. 3. (magnified). From Mr. Cuming's collection. 



g2 



