176 LITTORINIDA. 
var. filosa. 
Trochus filosus, Helbling, Privatg. Béhmen IV, 1779 (fide Mérch, 1876). 
Mérch does not record the following important locality. 
2 Florida ; coll. Prof. E. C. Stearns. 
5. Modulus unidens. 
Trochilus unidens, Zisteri, Chemn., Conch. Cab. JI, Vol. X, p. 290, 1788 ;= 
Monodonta carchedonicus,' Lam, 1822, Rab.?; fide Mérch =Trochus 
perlatus, Dillwyn, also Wood (not of Gmelin), and var, minor= 
Monodonta angulata, C. B. Adams, P. Bost. S. 1845, Jamaica. : 
7 Panama and Gulf of Fonseca; coll. Profs. E. C. Stearns and 
W. Newcomb. 
6. Modulus disculus. 
Trochus disculus, Philippi, Zeits. Malak. 1846, Mazatlan.. 
var. [fide Newcomb]. 
20 Gulf of California; coll. Profs, E. C. Stearns and W. Newcomb. 
7. Modulus obtusatus. 
Trochus obtusatus, Philippi, Conch, Cab. IT, 1846, Loc.?, for Chemnitz, 
JSiy. 1569—70. 
7 Mauritius and Ceylon; coll. G. Nevill, Esq., 
Despite the highly valued opinion of von Martens, I consider 
this a distinct species. 
1 Rodriguez; coll. J, Caldwell, Esq. 
A doubtful specimen ; in very bad condition. 
8. Modulus tectum. 
Trochus tectum, Gmelin, Syst. Lin. 1788, West Indies ; from Madagasear, 
Natal, Red Sea, Bourbon, fide v. Martens ; fide Petit = Monodonta 
retusa, Bruguiere = Modulus cidaris, Reeve. 
7 Mauritius and Seychelles; coll. G. Nevill, Esq. 
3 Natal; coll. G. Nevill, Esq. 
3 Trincomalee (?); exc, Dr. F, Stoliczka. 
