KREBS— WESTIXMAX RISSOINAE, 
3. liissoina sloaneana Orb, 
Orb. Moll . Cuba , pt. ii, p. 28, pi. xii, f. 36, 33 
8. v. M. op. cit. p. 112, f. 80. 
Habitat •* Westindies. 
4. Rissoina vitrea Adams 
C. B. Adams Contr. Conch., p. 113 
8. v. M. op. cit., p. 113, f. 82. 
Habitat .- Jamaica. 
With regard to the divisions adopted by Schwartz von 
Mohrenstern it seems that the division I is well founded ; 
but we do not agree with this author in the opinion that 
the form of the protuberance is constant, and sufficient for 
the distinction of species. Division II we do not consider 
tenable. The species here included we should regard as 
another subdivision (e) of division I • Shells with narrow 
longitudinal ribs , without distinct transverse lines , and a canal 
more or less distinct. In the species grouped in Schwartz’s 
subdivision a of division II the canal not to be seen in 
young examples. On the other hand in old specimens of 
subdivision b of the same division the canal is risible . 
Schwartz admits that R. dubiosa Adams, which he places 
under a of his Division II, may be a variety of R. bryenea 
or R. firmata, both of which belong to section b. These 
divisions are therefore not tenable. The divisions Ilf, IV, 
V, and VI are well characterized. 
The thirty-one species enumerated above are reduced by 
Schwartz to the following 17 : — 
Dissoina albida Adams (— affinis Adams ) 
browmiana Orb. (= laevissima Ad.) 
bryenea Mont, (scalarioides Ad.) 
