VARIETIES OF NASSA. 
Similar in form to the last, but cross-grooved, callous expanded. 
Smooth, polished, strongly ribbed throughout, without the 
nodules at the sutures; is the N. plicosa, Bolton. 
Strongly ribbed, but with very few cross-grooves, pure white 
inside and out. 
Ashy-grey, spotted between the nodules. South Africa. 
Darker in colour than the last, spots very pale. 
Two-banded externally and three in the interior. 
With a single external band and three inside. 
Pale buff, with a broadly-expanded callous, like the Helmet 
Conch. 
Yellow, tumid, double banded, sutures tumidly plicated, 
showing a tendency to run into the N. coronata, Brug. 
’ Rufous-brown, the interior is brown with a central, narrow, 
white band. 
Large, nodules prominent, olive-green. Reeve, pl. 4, f. 25a, 
callous much less expanded than is usual in these shells. 
Callous less expanded, showing a close affinity with the 
N. marginulata, Lam. 
A variety with an expanded callous; is figured in Kiener at 
pl2s, t. 11: 
Another variety with the cross-grooves interrupted ; is figured 
in Mart. and Chem., ed. 2, pl. 4, f. 19, 20. 
Ribs few and distant, shell white; is figured in Mart. and 
Chem., ed. 2, pl. 4, f. 21. 
Pulla, Reeve, pl. 4, f. 22. Linneeus. (?) A cancellated variety 
of N. arcularia, Linn. Philippines. 
White, with a central brown band and another of a darker 
colour below the sutures. 
Crenulata, Brug. Ency. Meth., pl. 394, f. 6, exclusive of all 
synonymes. 
Of a cream-colour, with very dark spots between the nodules, 
ribs broad ; two of the ribs unite in one tubercle, and this 
occurs in the three first tubercles behind the lip. 
Ribs very irregular, three of them join in the first tubercle, 
two and part of a third join ata little distance from the 
second, the remaining ribs are curiously curved. 
White or very pale, cancellation very close. Red Sea. 
Showing a close affinity with the N. perlata, Meuschen. 
5 4 with the N. hispida, A. Ad. 
