350 ODOSTOMIA. 



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

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



Eur-ope. 

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

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



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



Rather thin, nearl}^ transparent, glossy, no sculpture except 



microscopic growth-lines ; wiiorls 6 ; imperforate ; tooth small 



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



or stri£e. Length, 2'5 mill. 



Bridany, Tunis. 



Section Ondina, Folin, 1S70. 



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



Very 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. Warrent, Thompson. Figs. 11, 12. 



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

 more developed. 



0. Galvagni, Aradas, is a S3 non3'm. 



0. diaphana, Jeffreys. PL 77, fig. 9. 



Very thin, nearly transparent, lustrous, with microscopic 

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

 flexuous, deepl}' sinuous above, tooth obsolete; umbilicus devel- 

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



Eurojye. 

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



Pellucid, white, decussated b}- microscopic striae; wliorls 7, 

 convex, suture submargined ; columella obliquely uniplicate. 

 Length, 4 mill. 



Sicily. 

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



