138 MOLLUSCA. 
a dark ‘brown, somewhat velvety, periostracum, and.on the spots where this is lost a 
very fine punctuation of the shell, which leads me to believe that the most natural 
place for this species may be in the subgenus Trichodiscina. With H. (Solaropsis) 
tiloriensis there. isnot much similarity in the general appearance. 
Crosse 1-8 erroneously refers the locality “¢ Chiriqui lagoon” to Nicaragua. 
_ Subgen. PRATICOLELLA. 
Dorcasia (Gray), Binney, Terr. air-breath. Moll. N. Am. v. (Bull. Mus. Comp. Zoél. Harv. Coll. 
dv.) p. 846 (1878). 
Praticola, Strebel u. Pfeffer, in. Strebel’s Beitr. Mex. Land- und Siissw. -Conch., iv, p. 38 (1880) 
(preoccupied by Swainson, 1837, and,as Pratincola by K. L. Koch, 1816, both in Birds). 
Shell globose, of moderate size, perforated, smooth, or slightly striated ; peristome 
rather thickly tipped and reflexed. Jaw with flat, broad ribs. 
Glandula mucosa simple; retractor penis with double insertion (see Leidy, in | 
Binney’s Terr. air-breath. Moll. N. Am. i. p. 255, and Pfeffer in Strebel’s Heit loc. cit. 
p. 40). Dart-sac simple; dart‘as yet not described. 
Dorcasia, Gray, has as type the South African #. alexandri (Z, eitschr. fiir Malak. 
1845, p. 87, note), which differs considerably in general appearance. ulotella, Mousson, 
type HZ. similaris, Fér., agrees more nearly with Praticolella. | 
As the shells of this subgenus resemble in many respects those of the following, 
we may unite both in one table for facilitating their determination. | 
14. Helix ampla. 
Helix ampla, Pfr. in Malak. Blatt. xiii. p. 78 (1866) '; Monogr. Helic. Vivent. v. p. 63%. 
Helix (Patula) ampla, Fischer & t Crosse, Miss. Scient. a Mollusca, 1 1. p. 227° om not full- 
grown). : 
Praticola: ocampi, Strebel, Beitr. Mex. Land- und Siissw.-Conch. iv. p. 38, t. 2. fies. 2,5, and 
t. 10. figg. 1 (radula), 1 @ (jaw), 1 a~F (anatomy) *. 
Hab. E. Mexico: Misantla, on meadows, fields of Indian corn, &c., and Rancho de 
Guerrero near Misantla (Strebel +); Rio de Misantla (F. D. Godman); Almo- 
longa (Hége); Jalapa, in company with Leptomerus (Hoge); La Banderilla, 
Monte de ‘Tataquicapa and Dos Arroyos, all near Jalapa, on grass (Strebel 4); 
Mirador (Berendt and Strebel }~*) ; Consolapa near Coatepec and San Antonio del 
Monte (Strebel +). 
Somewhat variable with regard to the elevation of the spire; the young shell is 
obtusely angulated, and a trace of the angulation is sometimes to be seen in the first 
half of the last whorl. . 
This species resembles somewhat the widely distributed H. similaris, Fér., the range 
of which-extends to Brazil; but is distinct from it by the more globose form, the more 
