284 LEPTINARIA. 



This fine species is readily distinguished from the large 

 species of Obeliscus by its broader shape and thicker, clumsy 

 summit. Moricand states that it is found in virgin forest, 

 especially under the fallen leaves of Bromelia, and attains a 

 length of 120 mm., with 11 whorls. Pfeiffer records a speci- 

 men measuring 125 mm. long, 30 wide, aperture 29 mm., but 

 these are exceptional dimensions, not reached by any shell in 

 a large series before me. Born gives the length of his speci- 

 men as 3 inches 11 lines, about 98 mm. 



The uterine young (pi. 37, fig. 99, nat. size) are yellowish- 

 corneous, subcylindric with conic summit, and consist of 5% 

 whorls, of which the first 1% are glossy and almost smooth, 

 the rest covered with excessively fine and close striae, giving 

 it a silky luster. The base is glossy. Length 22, diam. 

 11 mm. 



Genus LEPTINARIA Beck. 



Leptinaria BECK, Index Molluscorum, p. 79 (1839). 

 SHUTTLEWORTH, Mittheil. nat. Ges. Bern, 1854. CROSSE & 

 FISCHER, Miss. Sci. Mex., Moll., i, p. 622 (anatomy of L. 

 lamellata). Nothus ALBERS, Die Heliceen, 1850, p. 168, sole 

 species B. anomalus, Achatina anomala Pfr. Not Nothus 

 (Coleoptera) Olivier, 1811, or of Billberg, 1820 (Lepidop- 

 tera). Lamellaxis STREBEL, Beitrag Mex. Land- und Siiss- 

 wasser-Conch., v, p. 109 (1882), first species L. mexicanus 

 Pfr. 



Shell ovate, oblong or turrite, perforate or imperforate, 

 thin, usually whitish-corneous, somewhat pellucid, composed 

 of 5 to 11 convex whorls. Embryonic shell smooth, with 

 rounded summit (except in the subgenus Pelatrinia). Aper- 

 ture ovate, the columellar margin reflexed, near the base 

 twisted, and notched or truncate; outer lip thin and simple ; 

 parietal wall sometimes bearing an entering lamella. 



Jaw thin, arcuate, finely striate vertically. 



Reproduction ovo- viviparous in the typical forms, but in 

 others by eggs similar to those of Opeas and Subulina. 



Dentition. In L. lamellata the radula has nearly hori- 

 zontal rows of 16, 12, 1, 12, 16 teeth. The middle tooth is 



