200 
Melania semicarinata, nob. Disseminator of Useful Knou'- 
ledge, vol 3. PI. 47, f. 4. 
Melania laqueata, nob. Disseminator of Useful Know- 
ledge, vol 3. PL 47, f. 1. 
Kanella. — Shell oval or oblong, more or less depressed in con- 
sequence of haying a range of varices only on each side, forming 
a somewhat oblique longitudinal series ; aperture oval, the labium 
being much arquated ; base canaliculated, sometimes a little emar- 
ginated ; a sinus at the superior termination of the labrum ; epider- 
mis distinct ; operculum horny ? 
Ohs. These are the Frog and Toad shells of collectors, a genus 
of well marked Marine shells dismembered by Lamarck from the 
Linnean Mur ex, in consequence of their lateral margined character. 
Montfort made another division of these shells ; to those with an 
umbilicated columella he gave the generic name of Apollon, and 
those which have no appearance of umbilicus he named Buffo ; 
these designations, or rather their corresponding words Appole and 
Crapaud, are adopted by Blainville as subgenera of Ranella. 
These shells are sufficiently distinct from those of any other group 
and cannot be mistaken, if we except a few species which approach 
Triton, (a name which ought to be changed, as it had been pre- 
viously applied as a scientific designation by Laurenti to a genus 
of Amphibia^ a genus which is distinguished by having its varices 
rare and not at the equal distances of half volutions from each 
other. The animal does not seem to be known, but judging by 
analogy, it probably resembles that of Triton and Murex and has 
therefore a horny operculum, composed of lamelliform elements, 
disposed in an imbricated manner, and commencing at the superior 
tip. It must also be carnivorous. 
Ranella caudata, nob. Jour. Acad. Nat. Sc. voldU, p. 236. 
Ohs. This is a common species on the coast of the United 
States. Its generic affinity is not always obvious, as in some 
specimens the varix of the aperture, only, is well formed. PI. 48. 
Cerithium. — Shell more or less turrited, often tubercular ; aper- 
ture small, oblique, with a short, truncated or recurved canal at 
base which is not emarginated ; labium concave, more or less dis- 
tinct, groove at the junction of the labrum with the preceding 
whorl; operculum small rounded. 
Animal much elongated ; mantle prolonged in a canal on the left 
