MEXICAN OPEAS. 211 



smooth ; sutures rather constricted ; aperture nearly orbicular ; 

 lip simple ; transparent horny. (Eve.) . 



Habitat unknown (Cuming coll.). 



Bulimus glomeratus RVE., Conch. Icon, v, pi. 80, f. 591 

 (Dec. 1849). PFB., Monogr. iii, p. 366; iv, 435; vi, 75; viii, 

 105 ; Conchyl. Cab. p. 133, pi. 42, f . 36-38. 



This form, which seems to belong close to 0. beckianum and 

 0. mimosarum, is still known by the original lot only. 

 Pfeiffer gives another figure (pi. 27, fig. 48) and a more de- 

 tailed description. "Shell subimperf orate, oblong- turrite, 

 thin, striatulate, pellucid, pale corneous; spire regularly 

 tapering, the apex obtuse. Whorls 9, moderately convex, the 

 last scarcely two-sevenths 'the total length, rounded basally; 

 columella subarcuate ; aperture diagonal, nearly semicircular ; 

 peristome thin, the margins somewhat converging, the right 

 margin narrowly expanded, columellar margin very shortly 

 reflexed, subappressed. Length 10, diam. 4 mm. ; aperture 

 3x2 mm." 



SPECIES OF MEXICO AND CENTRAL AMERICA. 

 Besides several widely spread species described above, and 

 those following, an undescribed 0. torulosa Morel, is credited 

 to Panama in Nevill's Handlist Ind. Museum, i, p. 163. 

 Strebel reports 0. rarum (no. 12) from eastern Mexico. 



16. 0. ARGUTUM n. sp. PI. 28, fig. 68 ; pi. 40, fig. 9. 



Shell very narrowly perforate, tapering-oblong, very thin, 

 corneous, subtransparent ; spire slowly tapering to a very 

 obtuse summit. Whorls 5y 2 to 6!/2, convex, the first 1% 

 smooth, the rest densely, arcuately and sharply striate the 

 striae obsolete on the nearly smooth base of the last whorl. 

 Aperture subvertical, ovate ; outer lip thin ; columella vertical, 

 weakly plicate obliquely near the base, its margin triangularly 

 reflexed above. 



Length 6.8, diam. 2.5, aperture 2 mm. (Orizaba). 



Length 6, diam. 2.3, aperture 2 mm. (Orizaba). 



Length 5.6, diam. 2, aperture 2 mm. (Texolo). 



Mexico: Orizaba, 500 ft. above the town (Heilprin exped.) ; 

 Texolo, State of Vera Cruz (S. N. Rhoads). 



