CONCHOLOGY. 117 
N. consolidata.* N. pusilla.* 
N. duplicata.* N. triseriata.* 
N. heros.* N. rugosa.* 
FAMILY XII. 
JANTHINEA. One genus. 
1. Genus Janthina. Pl. XI. 
Animal. Of oval form, spiral, provided with a circular concave 
foot, accompanied with a vesicular subcartilaginous mass, and 
natatory appendages on each side; head very thick; tentacula 
scarcely at all contractile; eyes situated beneath the extremity of 
long peduncles placed at the external side of the tentacula, and 
appearing to form a part of them; mouth at the extremity of a 
very thick proboscidiform muzzle, between two vertical, subcarti- 
laginous lips furnished with sharp spines. 
Shell. Of a beautiful violet colour, found in numbers floating 
on the surface of the ocean, suspended by a vesicular appendage 
which gives a rich purple stain. Extremely thin and fragile, spire 
low, lateral, pointed, with sibcarinated whorls; aperture large, 
subangular, modified by the last whorl of the spire, edges dis- 
united, the left formed by the columella, which is straight, con- 
tinuing beyond the base, right edge sharp, with a sinus in the 
middle. Inhabits the Atlantic Ocean. Three species. 
Janthina naticoides. Janthina communis, 
J. exigua, 
FAMILY XIII. 
Macrostomrana, Four genera. 
1. Genus Sigaretus. Pl. XI. 
Animai. Body oval, flat beneath; edges of the mantle ver- 
tical, thin, extending beyond the body in all directions, sloped 
anteriorly ; the mantle itself dilated superiorly. 
Sheil. More or less thick, internal, without colour, much de: 
