144 MOLLUSCA. 
fornia, by Binney and Bland (Land and Fresh-water Shells of N. Am. i. p. 171), Pteiffer 
(Monogr. Helic. Vivent. vii. p. 372), and Binney (Terr. air-breath. Moll. N. Am. v. 
p. 366, and Manual of Am. Land-Shells, p. 144); but I am unable to follow them in 
this, because the shell of the latter is expressly stated to have (under the lens) ‘ very 
minute spiral striations,”—a form of sculpture not visible in the Mexican shells before 
me, nor agreeing with Tryon’s words: ‘ punctate when viewed with a lens.” Also the 
figure given by Binney in both his works represents a more depressed shell, with a 
somewhat more open umbilicus; while Tryon’s figures agree very well with the shell 
from which my description is taken. 
Helix rowelli, Newcomb, from Lower California, may also be near this species, but 
it has a distinctly larger umbilicus. 
18. Helix magdalenensis. 
Helix (Arionta) magdalenensis, Stearns, Proc. U. 8. Nat. Mus. xii. p. 207, t. 15. figg. 11-18 
(magnified) (1890) *. 
Hab. N.W. Mexico: Magdalena, State of Sonora, among rocks on the top of a moun- 
tain, at an elevation of 1000 feet above the town (Bailey '). 
Very depressed, with open umbilicus. 
Subgen. Pomatia, Leach. 
Shell of relatively large size, globose, rather coarsely striate, with large subvertical 
aperture and nearly or wholly covered umbilicus. Coloration generally arranged in five 
bands, some of which may blend into each other or disappear. Jaw with stout ribs. 
Dart four-edged, crowned at its base. Two clusters of mucous glandule. 
A European subgenus, one species introduced by man in America. 
H., aspersa, Mill, Dilatato-globosa, imperforata, rugulosa et malleata, flavescens, fasciis fusco-marmoratis lati- 
usculis picta; apertura lunato-ovata, breviter reflexa. Diam. 30-38, alt. 25-36, apert. 15-25, anfr. 4— 
43 millim. 
19. Helix aspersa. (Tab. VII. fig. 19.) 
Cochlea vulgaris, “ major, pulla, maculata et fasciata, hortensis,” Lister, Hist. An. Angliz, ii. p. 113, 
t. 2. fig. 2, with a figure of the dart (1678) ’. 
Helix aspersa, O. Fr. Miller, Hist. Verm. ii. p. 59 (1774) *; Draparn. Hist. Nat. Moll. Terr. et 
Fluv. de la France, p. 89, t. 5. fig. 23°; Férussac, Hist. Nat. Moll. terr. et fluv. t. 18 (varie- 
ties of shell), t. 24. fig. 3 (living animal), t. 24. (copulation, eggs, dart) ‘, and Prodr. p. 30, 
no. 51 (1821)°; Rossm. Icon. d. Land- und Siissw. Moll. i. p. 35, t. 1. fig. 8, and t. 22. 
figg. 294, 295°; Pfr. Monogr. Helic. Vivent. i. p. 2417; Moquin-Tandon, Moll. terr. et 
fluv. de la France, ii. p. 174, t. 13. figg. 14-32 (anatomy) *; Ad. Schmidt, Geschlechts- 
Apparat d. Stylommatophoren, p. 15, t. 1. fig. 5 (anatomy) (1855) °; J effreys, Brit. Conch. 
i. p. 181, t. 6. figg. 7,8*°; Binney & Bland, Land and Fresh-water Shells of N. Am. i. 
p- 183, fig. 322"; Binney, Terr. air-breath. Moll. N. Am. ii. p- 116”; Stearns, Ann. N. 
