154 STREPTOSTYLA. 



forward in the middle, retracted above and below. Colu- 

 mella only moderately twisted, its face being a thin flange, 

 narrow in front view but wide as seen in profile. Length 

 13.2, diam. 6, aperture 9 mm. Another specimen measures, 

 length 14.3, diam. 6.1, aperture 9.1 mm. 



Yucatan: Tekanto (type loc.) and Ticul (Heilprin exped.). 



This species is closely related to 8. ventricosula, but differs 

 by its deeper suture and consequently much narrower sub- 

 sutural clear border, by the less swollen first whorl, more 

 cylindric last whorl, and the weaker columellar fold. It has 

 not the rapidly descending last whorl of S. sololensis, and the 

 columellar fold is not so strong as in S. meridana cobanensis. 

 It occurs with S. ventricosula and 8. meridana. 



24a. Var. distort*, n. v. PI. 30, fig. 92. 



A single specimen from Tekanto differs from the rest of 

 the series from that place in having the last half of the 

 second and first half of the third whorl very narrow, less than 

 half the width of the adjacent whorls above or below ; other- 

 wise like S. yucatanensis. Without a large series it is impos- 

 sible to say whether this is merely an individual variation or 

 indicates a separate species or race. Length 13.5, diam. 6, 

 aperture 9 mm. 



25. S. MERIDANA (Morelet). PI. 30, figs. 93, 94, 95, 96. 



' ' Shell ovate-oblong, somewhat solid, glossy, pellucid, tawny. 

 Whorls 6, flattened, with a submarginate suture. Columella 

 callous, spirally projecting, white, arcuately curved, the 

 truncation evanescent. Aperture narrow, irregularly oblong, 

 rounded basally more than half the length of the shell. 

 Length 12, diam. 4.5 mm." (Morelet). 



Yucatan: Merida (Morelet); Santa Ana near Calcehtok; 

 Tekanto; Ticul; hacienda of Tabi, and from between Sitil- 

 pech and Tunkas (Heilprin exped.). 



Glandina meridana MOREL., Testae. Noviss., i, p. 15 (1849). 

 Streptostyla m., MARTENS, Biologia, p. 101, pi. 5, f. 25. 

 Spiraxis cobanensis TRISTRAM, P. Z. S. 1861, p. 231. Cf. 

 MARTENS, 1. c., fig. 26. Streptostyla cornea C. & F., Journ. 



