350 ODOSTOMIA. 



strong, prominent, interior of lip ridged, terminating in small 

 tubercles within the mouth. Length, 6'25 mill. 



Europe. 



The synonyms include 0. polita, Bivona ; 0. Nayli, Brusina ; 

 0. sicula, Phil. ; 0. monodon, Requien ; 0. plica, Cantraine. 



O. TENUIS, Jeffreys. PI. 77, fig. 2. 



Rather thin, nearly transparent, glossy, no sculpture except 

 microscopic growth-lines ; whorls 6 ; im perforate ; tooth small 

 but conspicuous, interior of lip with half a dozen short grooves 

 or striae. Length, 2'5 mill. 



Brittany, Tunis. 



Section ONDINA, Folin, 1870. 

 0. OBLIQUA, Adler. PL 77, figs. 10-12. 



Yery thin, transparent, glossy, with fine, close spiral striae, 

 becoming coarser on the base, whitish ; whorls 5, suture deep 

 and oblique; outer lip flexuous, retreating, sinuated above, 

 smooth within, tooth only a slight obscure fold ; umbilicus none, 

 or a very small chink. Length, 5 mill. 



Europe. 



0. exilissima, Brusina, is a probable synonym. 



Var. WAERENI, Thompson. Figs. 11, 12. 



Smaller, with the basal striae more distinct, and the umbilicus 

 more developed. 



0. Galvagni, Aradas, is a S3 - nonym. 



0. DIAPHANA, Jeffreys. PI. 77, fig. 9. 



Very thin, nearly transparent, lustrous, with microscopic 

 growth-lines, whitish ; whorls 5, suture narrow, oblique ; outer lip 

 flexuous, deeply sinuous above, tooth obsolete; umbilicus devel- 

 oped in the adult only, insignificant. Length, 2'5 mill. 



Europe. 

 0. ELEGANS, Monts. PL 77, fig. 13. 



Pellucid, white, decussated Ity microscopic striae; whorls 7, 

 convex, suture submargined ; columella obliquely uniplicate. 

 Length, 4 mill. 



Sicily. 

 It is 0. mtrea, Brusina, not A. Ad. ; 0. neglecta, Tiberi, not 



