176 MOLLUSCA. 
venting the entrance of beetles, &c. Jaw slightly striated. (Morch, Journ. de Conch. 
xiii. p. 381.) 
Labyrinthus is nearly confined to the northern part of South America, extending 
only into the more southern parts of Central America ; in Costa Rica it is represented 
by two species of small size and somewhat simple structure of the aperture. ‘Towards 
the south it reaches, so far as we know, only to the river Amazon (L. yatest, Pir.) and its 
upper confluents in Eastern Peru (L. furcillatus, Hupé *, and L. tarapotonensis, Moric.). 
1. Labyrinthus triplicatus. (Tab. X. figg. 2, 2 a-c.) 
Helix triplicata, v. Mart. in Malak. Blatt. xv. p. 468 (1868) *; Pfr. Novitat. Conchol. iii. p. 460, 
t. 101. figg. 1-3°; Monogr. Helic. Vivent. vii. p. 463°. 
Helix esopus, Angas, P. Z. S. 1878, p. 72, t. 5. figg. 11, 12°, and 1879, p. 476 , 
Testa anguste umbilicata, depresse conoidea, obtuse angulata, solida, striata, minute granulata, violaceo-fusca, 
ad peripheriam pallidior; anfractus 5, ultimus basi convexiusculus, antice deflexus et subtus strangulatus ; 
apertura subhorizontalis, oblongo-auriformis ; peristoma carneum, incrassatum, continuum; margo parie- 
talis solutus et breviter erectus, infra umbilicum cum basali conjunctus; margo superior inflexus; margo 
basalis inde ab umbilico substrictus, medio callosus, tum leviter descendens et plica obtusa nodiformi 
munitus ; pars externa peristomatis rotundata, intus plica brevi, compressa, oblique antrorsum vergente 
munita ; paries aperturalis lamina valde compressa, simplice, marginem non attingente munitus. 
Diam. maj. 25, min. 21, alt. 12; aperture (incluso peristomate) diam. 14, lat. 8 millim. 
Hab. E. Costa Rica (Carmiol }-*); Buenavista, 3000 feet above the sea (Boucard *) ; 
coast region and hills of Uren, 3000 feet above the sea (add °). 
“ Animal grey above, with the foot nearly white” (Gabd°). I have seen two 
specimens of this species: in one of them the plait behind the external part of the 
peristome is obtusely rounded in its fore part, and in the other it is acutely pointed ; 
in other respects they agree with each other. 
2. Labyrinthus quadridentatus. 
Carocolla quadridentata, Broderip, P. Z.S. 1832, p: 30°. 
Helix quadridentata (Brod.), Pfr. Monogr. Helic. Vivent. i. p. 899°; Martini & Chemnitz, Syst. 
Conch.-Cab. ed. 2, Helix, i. p. 271. no. 752, t. 128. figg. 9-11°; Reeve, Conch. Icon. vii., 
Helix, t. 101. fig. 557°. 
Testa anguste umbilicata, subdepresse conica, distincte angulata, solida, striatula, minute granulata, rufo- 
fusca; anfractus 5, ultimus basi paullulum convexus, antice deflexus et leviter constrictus ; apertura fere 
horizontalis, oblongo-triangula ; peristoma albidum, incrassatum, continuum ; margo parietalis solutus et 
breviter elevatus, oblique transversus, infra umbilicum cum basali conjunctus ; margo superior patulus, 
inflexus ; margo basalis reflexus, medio antrorsum convexus et biplicatus, plica interiore nodiformi, non 
intrante, ceteriore compressa, intrante ; pars externa peristomatis rotundata, intus plica brevi, valde com- 
pressa, elate triangulari, marginem non attingente munita ; paries aperturalis lamina valde compressa, 
flexuosa, sat longa, marginem non attingente munitus, 
Diam. maj. 20, min. 18, alt. 11; apert. diam. 11, lat. 7 millim. 
Hab. 8.W. Costa Rica: woods near the Golfo Dulce (Cuming 1); Terraba, at an eleva- 
tion of 200 to 300 metres, in woods (H. Pittier, 1891). 
* Hela furcillata, Hupé, in Pfeiffer’s Monogr. Helic. Vivent. vii. p. 462, is stated to be from “ Panama,” 
but this is probably a misprint for “ Peruvia.” 
