PTEROPOUA. 145 



dorsal ridge is a little tortuous, and the apex is very slightly 

 curved. 



29. SPINIFERA. f. 43, 44, Rang. — Quam G. aciculata 

 latior brevior, carina dorsali magis tortua. — Much broader 

 and shorter than sp. 28, with the dorsal ridge more 

 tortuous. 



30. ROTUNDA, f. 47, 48, Soioerhy. — Quam praecedentes 

 magis obtusa ; carina dorsali et apice obtusis. — More blunt 

 than the preceding at all points ; shorter and wider than 

 sp. 29. 



31. STRIATA, f. 38, Rang. — Latiuscula, recta tenuiter undu- 

 latim annulata, apice acuminate. — Shorter and more widely 

 pyramidal than G. spinifera, very finely ringed. 



32. viRGULA, f. 39, 40, Rang. — Eotunda cylindrica ; 

 apertura simplici ; apice obtuso, leviter arcuato. — A very 

 simple tubular form, with the apex blunt and slightly bent. 



33. coRNiFORMis, f. 4 1 , 42, Orbigny. — Quam G. virgula ad 

 apicem magis recurva, acuta. — The apex is pointed and finely 

 recurved. 



Triptera. 



33*. COLUMNELLA, f. 49, Rang. — Bulbiformis, versus termi- 

 num ventricosa, ad terminum obtusa, lamina parva annulata ; 

 apertura contracta ovata compressa. — A little bottle-shaped 

 shell, with obtuse termination. 



Genus SPIRT ALTS, Souleyet. 



Testa spiralis, fusiformis vel heliciformis, sinistralis, 

 hyalina ; columella plerumque acuta, labio externo tenui. 

 Operculum ovatum, paucispirale. — The change from tubular 



L L 



