MOLLUSCA. 605 
Helicina fragilis (p. 35). 
Helicina fragilis, Pilsbry, Proc. Acad. Phil. 1894, p. 332"; Fischer & Crosse, Miss. Scient. Mex., 
3 
Moll. ii. p. 420, t. 57. figg. 7, 7 a,b (var. merdigera), 8, 8a,6 (var. elata), and 9, 9a,b 
(normal form) *, 
To the localities given, add :— 
Hab. [E. Mexico :] Orizaba (Heilprin 32), 
A. Sallé13 has observed that this species covers itself with its own excrement, 
probably for protection. The European Buliminus (Merdigerus) obscurus and some 
species of Pupa have a similar habit. 
Helicina succincta (p. 36). 
Helicina succincta, Fischer & Crosse, Miss. Scient. Mex., Moll. ii. p. 422°. 
Helicina raresulcata (p. 36). 
Helicina raresulcata, Fischer & Crosse, Miss. Scient. Mex., Moll. ii. p. 423°. 
Helicina arenicola (p. 36). 
Helicina arenicola, Pilsbry, Proc. Acad. Phil. 1891, p. 3327; Fischer & Crosse, Miss. Scient. Mex., 
Moll. ii. p. 424, t. 56. figg. 8, 8 a—c®. 
To the locality given, add :— 
Hab. {N. Yucatan:] Silam, Ticul, Labna, Tabi, Uxmal, Tunkas, Santa Ana near 
Calcehtok, and between Sitilpech and Tunkas, most abundant, as variable in 
coloration as H. orbiculata, Say (Heilprin’). 
Helicina punctisulcata (p. 36). 
Helicina punctisulcata, Fischer & Crosse, Miss. Scient. Mex., Moll. ii. p. 427°. 
Helicina durangoana (p. 37). 
Helicina durangoana, Fischer & Crosse, Miss. Scient. Mex., Moll. ii. p. 426, t. 56. figg. 7, 7 a-c’. 
These authors! think that this species belongs to the group of H. zephyrina. 
Helicina delicatula (p. 37). 
Helicina delicatula, Fischer & Crosse, Miss. Scient. Mex., Moll. ii. p. 427, t. 57. figg. 3, 3a-c 
(var. unicolor), and 4, 44°. 
Helicina oweniana (p. 38). 
Helicina oweniana, Pilsbry, Proc. Acad. Phil. 1892, p. 339“; Fischer & Crosse, Miss. Scient. 
Mex., Moll. ii. p. 429, t. 56. figg. 4, 4.6,c¢ (normal form), 4a@ and 5, 5 a (var. coccinostoma), 
t. 57. figg. 5,5a-c (var. anozona)”’; Biolley, Mol. terr. y fluv. de Costa Rica, p. 5 
(var. anozona) “*. 
