96 BRACK YPODELLA, JAMAICAN. 



which is slight and obtuse a little above the middle of the last 

 whorl; spire with the outlines quite convex throughout most 



of the shell ; apex truncate, with the loss of whorls ; 10% 



whorls remaining, quite convex, with a deep suture ; last whorl 

 slightly produced. Aperture angular at the anterior extrem- 

 ity and on the middle of the right side; lip thin, sharp, nar- 

 row, and moderately reflected. Length .315, breadth .1 inch ' ' 

 (Ad.). 



Jamaica (C. B. Adams). 



Cylindrella simplex C. B. A., Contrib. to Conch., no. 2, p. 

 22, 39 (Oct., 1849). PFR., Monogr., iii, p. 573. 



Known to me by the above description only. 



43. B. HUMILIS (C. B. Adams). 



" Shell cylindrical in the lower two-fifths, tapering above; 

 pale horn color, with rather numerous oblique, nearly straight 

 equidistant, fine, elevated, transverse lines; spire truncate, 



with the loss of whorls; whorls remaining 8 to 8%, very 



convex, with a well-impressed suture; last whorl subangular 

 anteriorly, scarcely produced from the penult, whorl; aper- 

 ture orbicular, moderately large ; labrum moderately reflected 

 and dilated, very thin. Length .2, breadth .05 inch " (Ad.). 



Jamaica (C. B. Adams). 



Cyl. humilis C. B. A., Contrib. to Conch., no. 7, p. 101 

 (1850). PFR., Monogr., iii, p. 573. 



This very small species (length 5 mm.) is known to me by 

 Adams' description only. 



Subgenus MYCHOSTOMA Albers, 1850. 



Mychostoma (in part) ALB., Die Hel., 1850, p. 207, for C. 

 subula, collaris, gracilicollis, hanleyana, pallida, seminuda. 

 v. MARTENS, Die Hel., edit. 2, p. 37, type C. subula. PFR., 

 Nomencl. Hel. Viv., p. 279. PILS. & VAN., Proc. A. N. S. 

 Phila., 1898, p. 279. 



Shell long, truncate, slenderly cylindric or pillar-shaped, 

 white, finely striate, whorls numerous, nearly flat, the last be- 

 coming free, projecting, acutely keeled below, angular out- 

 wardly. Aperture rounded or squarish, as long as wide, gut- 



