158 MOLLUSCA. 
27. Helix adela. 
Helix adela, Angas, P. Z.8. 1878, p. 72, t. 5. figg. 8-10". 
Hab. Costa Rica: Navarro, on trees (Boucard 1). 
Chiefly distinct from the following by the whorls not being keeled. 
28. Helix costaricensis. 
Helix costaricensis, Roth, in Pfeiffer’s Novitat. Conch. i. p. 78, t. 21. figg. 15-17°; Pfr. Monogr. 
Helic. Vivent. iv. p. 302°. 
Helicigona (Planispira?) costaricensis (Roth), Mérch, in Malak. Blatt. vi. p. 111 (1859) °. 
Helix boucardi, Angas, P. Z.S. 1878, p. 72, t. 5. figg. 5-7“; P. Z.S. 1879, p. 476°. 
Helix costaricensis, var. steiniana, and forma virginea, Ancey, Bull. Soc. Malac. Fr. vii. pp. 155, 156 
(1890) °. 
Hab. Costa Rica (Wagner, 185312; Orsted’; Carmiol and von Seebach, in mus. Berol.) ; 
Navarro, on leaves of trees (Boucard *); high hills only, commonest in Cabecar 
(Gabb >). 
‘«¢ Animal dark grey above, foot white” (Gabbd) >. One or two bands are visible on 
the upper side—one halfway between suture and keel and one immediately above the 
keel, corresponding to nos. 2 and 3 in Helix nemoralis ; the upper one (no. 2) is very 
often, the other (no. 3) rarely, wanting ; in one specimen both are combined into one 
large band —, £3——. The upper side is more or less strongly convex. The 
lower side has a slight excavation immediately below the blunt keel, this at first sight 
having the appearance of a band. 
29. Helix guillarmodi. 
Helix guillarmodi, Shuttl. in Bern Mittheil. 1852 (Diagn. no. 2, p.19), p. 199°; Pfr. in Martini & 
Chemnitz, Syst. Conch.-Cab. ed. 2, Helix, ii. p. 413. no. 966, t. 147. figg. 5-7°; Monogr. 
Helic. Vivent. ill. p. 206°; Reeve, Conch. Icon. vii., Helix, t. 104. fig. 576%. 
Helix (Corasia) guillarmodi (Shuttl.), Fisch. & Crosse, Miss. Scient. Mex., Mollusca, i. p. 296, t. 10. 
figg. 8, 8a’. 
Axina guillarmodi (Shuttl.), H. & A. Adams, Gen. Moll. ii. p. 193°. 
Corasia guillarmodi (Shuttl.), Strebel, Beitr. Mex. Land- und Siissw.-Conch. iv. p. 507. 
Hab. E. Mexico: Toxpam, near Cordova, on leaves of trees (Sallé 5, Strebel"); Cerro 
de Palmas, near Cordova (Hége); Vera Cruz (Guillarmod 1*). 
In its depressed form, very sharp keel, and coloration, H. guillarmodi bears 
some resemblance to certain species from the Philippines which form the subgenus 
Corasia; nevertheless, 1 do not suppose that it is really allied to them, but, on the 
contrary, to such Central-American forms as H. costaricensis, H. salleana, &c. 
Ordinarily only two bands are present—one close above and one below the keel, 
corresponding to nos. 8 and 4 of H. nemoralis; but in some specimens an upper 
one, very narrow, near the suture, is also visible, and in others beyond this near the 
