258 New Land Shells from Costa Rica. 



the latter character it also differs from Vitrinoconus. It has 

 the shell, and probably, the appendiculate mantle, of Helica- 

 rion / but that genus has a horn-shaped process over its 

 caudal pore. 



Its lingual membrane resembles that of Limax agrestis in 

 having the inner, abnormal side cutting point to its first lateral 

 teeth. All the marginals are bifid. 



For geographical distribution see below, under V. Gdbbi. 



Velifera G-abbi, n. sp. 



Animal (pi. xi, fig. A) blunt before, tapering behind: greenish., with a con- 

 tinuous black band above the margin of the foot, and a second band broader 

 and a little higher up, broken by oblique light lines ; median line of back 

 nearly white: mantle apparently with two processes, one on the right, the 

 other on the left, half enveloping the shell. It has the peculiarity, when 

 distressed, as with the warmth of the hand, of throwing itself, like a worm, 

 with vigorous blows of its tail. Caudal pore without overhanging process 

 (plate si, fig. D). 



Shell (pi. xi, fig. B) imperforate, globose, very thin, pellucid, dark green- 

 ish brown; suture impressed; spire short, elevated; whorls 3; aperture 

 rounded, slightly oblique : peristome simple, flexuose above, scarcely re- 

 flected below. Greater diam. 6, lesser 5, height 3 mill. 



Locality, Flanks of Pico Blanco, 3000 feet. 



For jaw and lingual dentition, see generic description. 

 Teeth, 30-12-1-12-30. 



Plate xi, fig. E, represents a species very nearly allied to, if 

 not identical with, V. Gabbi, from 3000-6000 feet elevation of 

 Pico Blanco. It resembles in outline D'Orbigny's figure of 

 Helix jprogastor (Voy. l'Amer. Merid., pi. xvii, fig. 12-15). I 

 received a lingual membrane as belonging to this shell, and 

 figure it on plate xi, fig. F ; though I cannot help suspecting 

 that it belongs to some species of JBulimulus. I did not my- 

 self extract it from the shell. 



Cryptostrakon,* n. g. 



Animal (pi. xi, fig. H, central figure) slug-like, cylindrical, attenuated be- 

 hind ; mantle slightly anterior, thin, small, oval, entirely covering the shell ; 

 distinct locomotive disk? ; no caudal mucus pore; respiratory orifice on the 



* Kpv7tro5 } offtpcxKOv, concealed shell. 



