496 
Subfamily ZONITINZ. 
Genus Euconutus Reinhardt. 
Euconulus fulvus (Miller). Moll. Chi. Area, Pl. XXVIII, Fig. 17. 
Stations XXVIII, XXXIV. 
Genus VITREA Fitzinger. 
Vitrea hammonts (Strom). Moll. Chi. Area, Pl. XXVIII, Fig. 10. 
Stations V, XXVIII, XXX. 
Vitrea indentata (Say). Moll. Chi. Area, Pl. XXVIII, Fig. 11. 
Stations XXIV, XXVIII. 
Superfamily HOLopopa. 
Family HELICIDA. 
Subfamily POLYGYRINZ. 
Genus Potycyra (Say) Pilsbry. 
Section Triodopsis Rafinesque. 
Polygyra albolabris (Say). Moll. Chi. Area, Pl. X XIX, Fig. 6 
Stations V, VIII, XXX, XXXIII. 
Polygyra thyroides (Say). Moll. Chi. Area, Pl. XXIX, Fig. 2. 
Stations V, XII, XXVIII, XXX. About half of the adult speci- 
mens have the parietal tooth more or less developed. 
Section Stenotrema Rafinesque. 
Polygyra fraterna (Say). Moll. Chi. Area, Pl. XXX, Fig. 3. 
Stations V, VIII, XII. Fraterna exhibits two quite distinct forms: 
one is small and quite umbilicated; the other is larger and either im- 
perforate or only slightly umbilicated. The umbilicated form is 
larger than Polygyra monodon (Rackett). The two forms live in the 
same area and intergrade more or less completely. 
