214 MEXICAN OPEAS. 



tural side at the lower half. Length 10.8, diam. 3, aperture 

 2.5 x 1.3 mm. ; whorls 8y 2 . (Strebel) . 



Guatemala: Coban (Sarg, type loc.) ; Antigua, on moist 

 walls (Stoll). Also along the Rio Goto in the Golfo Dulce, 

 Costa Eica (Pittier). 



Opeas guatemalensis STREBEL, Beitrag Mex. Land- und 

 Susswasser-Conchyl. v, 1882, p. 105, pi. 7, f. 2a. MARTENS, 

 Biologia p. 293,' with var. majus, pi. 17, f. 7. 



This form differs from 0. subula as follows : the shell is 

 less acuminate, the whorls are comparatively lower, increase 

 more slowly in breadth, and are less convex ; the last is weakly 

 keeled, and in dorsal view appears not so tapering downwards. 

 The sculpture is not so sharp and is somewhat more irregu- 

 lar (Strebel). 



Strebel also reports a form of the species from Colombia, of 

 somewhat wider contour, especially below, and with somewhat 

 coarser sculpture (Beitrag pi. 7, f. 3; pi. 17, f. 26). He also 

 reports it from Ecuador. 



Var. majus Martens. PI. 29, fig. 89. 



Very solid, pale yellowish, somewhat shining, finely stri- 

 ated ; whorls 9, somewhat angulate and whitish at the suture, 

 which is rather deep. Columellar margin of the aperture 

 straight, vertical, broad, provided with a very fine fold, which 

 runs from inside obliquely to the middle of the outer margin. 

 Length 15, diam. 3.5, aperture 3.5 x 2 mm.; whorls 9. 

 (Martens) . 



W. Guatemala: Miramar, near San Francisco, in the Costa 

 Cuca (Stoll). 



21. 0. GLADIOLUS Crosse et Fischer. PI. 29, figs. 93. 



Shell covered-rimate, long, subulate-turrited, thin, slightly 

 striatulate, diaphanous, pale waxy-whitish. Spire much 

 lengthened, the apex rather obtuse, suture much impressed. 

 Whorls 12, rather flat, the embryonic 2 smooth, the last whorl 

 much shorter than the spire, tapering basally. Aperture sub- 

 vertical, subovate, colored within like the outside; peristome 

 simple, unexpanded, the margins remote, columellar margin 

 somewhat dilated, covering the umbilical crevice in part, 



