318 MOLLUSCA. 
6. Leptinaria exigua, sp.n. (Tab. XVIII. fig. 10.) 
Testa ovata, perforata, tenuis, levissime striatula, nitidula, pellucida, plus minusve albo-variegata ; anfr. 5, sat 
convexi, sutura compressa, superiores distincte costulati, ultimus versus basin bene rotundatus. Apertura 
modice obliqua, trapezoideo-piriformis, margine exteriore modice arcuato, non arcuatim producto, basali 
subanguste rotundato ; margo columellaris superne late dilatatus, versus basin angustatus, leviter tortus ; 
paries aperturalis callo nullo. 
Long. 5, diam. 3; apert. long. 3, diam. 2 millim. 
Last whorl, seen from the dorsal side, to the whole length of the shell as 1: 13. 
Hab. S.E. Mexico: Teapa in Tabasco (H. H. Smith). 
Distinct from ZL. guatemalensis, Cr. & Fisch., and from L. martensi, var. inflata, 
by the want of coste on the last whorl and by the size. Both the sculpture and the 
columellar fold are very feebly developed, but the general appearance of the shell is 
that of a true Leptinaria. The two specimens seen are of equal size. ‘The whorl 
before the last in one of them is distinctly costate, in the other with obsolete coste. 
Both shells have somewhat the aspect of not being full-grown, but I know no other 
species to which they could be attributed as a young state. 
7. Leptinaria interstriata. 
Tornatellina interstriata, Tate, Amer. Journ. Conch. v. p. 957, t. 16. fig. 3 (1869-70)*; Pfr. Monogr. 
Helic. Vivent. viii. p. 259”. 
Leptinaria interstriata, Angas, P. Z.S8. 1879, p. 485°. 
Hab. S.W. Costa Rica: on burned soil in the plains of the Rio Grande of Terraba, 
20 metres above the sea (Pettier, April 1892: one specimen). 
S.E. Costa Rica: without nearer indication of locality (Gabé >). 
N. Panama: Boca del Toro, on an island in the lagoon of Boca del Toro, in the 
forest (Tate 1 2). 
Distinct by its conoidal form and well-defined coste. 
8. Leptinaria crenulata, sp.n. (Tab. XVIII. fig. 12.) 
Testa acute ovata, rimato-perforata, solidula, costulis subdistantibus membranaceis, in anfractu ultimo evanes- 
centibus et striis subtilibus interjacentibus sculpta, flavescenti-albida, nitidula; anfr. 6, planiusculi, sutwra 
angulo limbata et subtiliter crenulata, ultimus basi sat tumidus. Apertura paulum obliqua, ovata, margine 
externo leviter arcuatim producto, basali latiuscule rotundato; margo columellaris in parte tertia inferiore 
tenuis, verticaliter ascendens, in partibus 2 superioribus latus, paulum concavus et plica tenui distincta 
spirali circumvolutus, non dentatus ; paries aperturalis callo tenui supra emarginato tectus. 
Long. 11, diam. 6; apert. long. 5, diam. 3 millim. 
Last whorl, seen from the dorsal side, is to the whole length of the shell as 1: 2. 
Hab. E. Costa Rica: Uren, near Talamanca (Pittier, March 1895). 
The angular line bordering the suture is distinctly visible when the shell is viewed 
in certain positions, but in others it appears only as a sudden change in the convexity ; 
it is more distinct in the last whorl. The crenulation or indentation of the suture is 
rather faint. I have seen only one specimen, which shows, at some distance behind the 
