294 Rev. R. T. Lowe on Melampus, &c. 
3?  Auricula Nucleus, Féruss., Tabl. Syst. p- 105, No. 26. 
“© Helix Nucleus, Gmel., Syst. Nat. p. 3651.” 
Martyn, Univers. Conch. tom. II., tab. 68, fig. exter. 
a) Knorr, Vergn. tom. VI., tab. 17, f. 9. 
Hab. Otaiti, Martyn. 
** On ne conndit point les animaux des deux espéces de ce groupe, qui 
ont une forme si remarquable. Tout porte cependant 4 croire qu’elles 
sont du méme genre que celles des groupes précédents.” Féruss. 1. c. 
It is very possible that several species associated with Tornatella, from 
which, however, they are distinguished by the thickness and solidity of 
their shells, together with a certain smoothness of surface, uniformity 
of colour, and habit, may hereafter be found to rank under the present 
genus, e. g. Tornatella nitidula, Lam. 
Auricula Dombeiana, Lam., and Voluta fluviatilis and fluminea, 
Maton, with other truly fluviatile species, will probably be found, when 
their animals are known, either to forma genus of themselves, as sug- 
gested by Sowerby, or at least not to unite generically with the Melam- 
podes. 
It only remains to point out how Melampus is distinguished from the 
several genera with which it is most likely to be confounded. It differs 
from Auricula (taking Aur. Mide, Jude, &c. as typical species of that 
genus,) in being one of the Marine Pectinibranchia ; while in respect to 
those species just mentioned, the evidence at least preponderates in favour 
of their belonging to the Land Pu/monea. Should they also be found here- 
after to have four tentacula, it is possible they may be united to the He- 
lices, as Férussac has already done with Auricula Sileni, auris leporis, 
bovina, and caprella of Lamarck ; in which case the genus 4uricula will 
be left without a single representative, 4ur. minima having been 
long ago by Miller called Carychium, and Aur. Scarabeus, Lam., having 
also been separated by Férussac, under the name of Scarabus, and hav- 
ing, like Carychium, only two tentacula. If they prove to have two 
tentacula, and be really at the same time terrestrial Pulmonea, which is 
perhaps the most probable supposition, the genus Scarabus of Férussac 
may perhaps merge into one with them; for which the name Auricula 
should unquestionably be preserved. And in either case, the name Au- 
