58 MALACOZOA. GASTEROPODA. PECTINIBRANCHIATA, 



opaque, of five rounded turns reticulated with longitu* 

 dinal and transverse slender ridges, the aperture roundish, 

 the outer lip thickened externally. Reticuldtus, covered 

 with net-work. 



9. Rissoa Pullus. Shell ovate, of five little convex, 

 glossy turns, the last as long as the spire, and banded 

 with red ; the aperture roundish-ovate. Pullus, a 

 chicken, or any young animal. 



10. Rissoa tristridta. Shell ovate, of five convex, 

 glossy turns, having three impressed lines along their 

 upper margin, the last with three rows of rhomboidal 

 red spots ; the aperture roundish. Tristridtus, with 

 three striae. 



11. Rissoa truncdta. -'Shell oblong, subcylindrical, 

 abruptly obtuse, of five turns, separated by a distinct 

 suture, and transversely striato-sulcate ; the aperture 

 ovate. TruncdtuSy abruptly terminated. 



12. Eissoa stridta. Shell oblongo-turrite, subcylin- 

 drical, opaque, of six rounded, spirally striate turns, with 

 obsolete ribs at their upper margin ; the outer lip pro- 

 jecting and considerably thickened. Stridtus, striated, 

 scored with lines. 



13. Rissoa grdcilis. Shell turrite, subcylindrical, thin, 

 pellucid, glossy, of six turns, the aperture ovate, little 

 narrowed behind, the outer lip thickened. Grdcilis, 

 slender. 



FAMILY IV. TORNATELLINA. 



Shell spiral, ovate, oblong, or turrite, with the aperture 

 oblique, ovate, oblong, or narrow, entire anteriorly, nar- 

 rowed behind by the convexity of the last turn, the inner 

 lip ending in an oblique plait on the columella. Named 

 from the genus Tornatella. 



GENUS I. ODOSTOMIA. Shell ovato-conical, with the 

 apex rather obtuse or mammillate, the^aperture suboval, 

 the peristome incomplete behind, and having a tooth- 

 like plait. 'Odovs, tooth ; o-ro>a, mouth. Fleming. 



1 . Odostomia unidentdta. Shell ovate, of four or five 

 moderately convex, glossy turns, the last ventricose, 



