208 SHELLS AND SHELL- FISH. PART I. 



vious to be overlooked. From the MS. notes of Guildifg, 

 it appears that these little shells are not more terrestrial 

 than the other marine TurhincB. In regard to amphibious 

 Testacea, or such as live both in and out of water, the 

 following valuable remarks are taken from the Guilding 

 MSS. " The genus Melampus commonly inhabits the 

 shallow parts of the coasts, but I have receiNedi Melaynpus 

 coniformis } from stagnant fresh waters on the shores of 

 Tortola, which only communicate with the sea occasion- 

 ally during heavy rains, when the accumulated water is 

 discharged with it. They are found creeping on the 

 mangrove roots ; and, like manyof the NeritidcB and Tur~ 

 hinidce, are perfectly amphibious, and very tenacious of 

 life. The latter, indeed, though they descend to feed at 

 night, are often seen on the trees of the coasts, and on the 

 dark black rocks elevated above the surface at high water ; 

 they remain stationary on the latter during the hottest 

 hours, even when it is painful to walk on them from 

 their great heat. The difference of the waters inhabited 

 by testaceous Mollusca does not, as was once supposed, 

 offer a certain guide for the division of genera. Many 

 of the JVeritince, for instance, dwell in the fresh waters 

 of rivers, while I have dredged up others in the bays and 

 shallows of the ocean." * 



( 1 92.) This genus, as far as we Cvin at present judge, 

 seems to be composed of the following groups : — Geo- 

 vula Sw., Melampus Montf., Rhodostoma Sw., Pedipes 

 Adanson, and Scarabus Montf. All these are clearly 

 separated from the sub-genera of Turbo by the total 

 want of an operculum ; while from Auricula they are 

 still further removed by the branchia being pectinated, 

 by having two tentacula, with the eyes at the base, or 

 sessile, and in the shells being more solid. The highly 

 interesting and valuable essay by Mr. Lowe on Pedipes 

 and Melampus t, satisfactorily proves that these cannot 

 belong to the Pulmonaria of Cuvier, and are therefore 

 excluded from the lanl shells, or HcUcidce. But 

 whether the genera Geovula and Scarabus have their 



« Guilding's MSS. f Zool. Jourii No. xix. p.281. 



