A9A MOLLUSCA. 
broad, rounded at the extremities. Colour violaceous, deeper at the 
spire. 
Length, including the keel, three-eighths of an inch; breadth one- 
twelfth of an inch. 
Found in the stomach of a Bonito, taken in latitude 3° S., long. 
20° W. 
This is a large shell, agreeing in colour with the species first de- 
scribed; but it is larger, less compressed, and the aperture is quite 
different. Described from a figure by Mr. Drayton. 
Figures 599, 599 a, lateral and superior views of the shell, enlarged ; 
599 b, natural size. 
ATLANTA TESSELLATA (Gould). 
T. nautiloidea, compressa, carina angustata cincta: anfractus quatuor, 
maculis quadratis violacets seriatim dispositis ornati ; ultimo anfractu 
cito crescente: apertura angusta, ad angulum internum rotundata. 
SHELL nautiloid, compressed, the last whorl somewhat rapidly en- 
larging ; whorls four, with a very narrow keel around the angle: aper- 
ture narrow, oval, rounded at the inner extremity, acute at the outer 
angle: colour yellowish, with a series of square, violaceous spots fol- 
lowing around the middle of the spire. 
Greatest diameter one-fourth of an inch; transverse diameter one- 
fortieth of an inch. 
Found with the preceding. 
The remarkable series of quadrate spots is a very obvious distinctive 
character of this species. 
Figures 600, 600 a, two views of the shell, enlarged; 600 4, natural 
size. 
