194 AMERICAN OPEAS. 



Land Shells, p. 425 (Ft. Dallas, Fla. ; Charleston, S. C.).- 

 ANGAS, P. Z. S. 1879, p. 485 (Costa Rica). SMITH. Journ. 

 Linn. Soc. London xx, Zool., p. 502 (Fernando Noronha). 

 Opeas octonoides Crosse, Journ. de Conch., 1890, p. 246 

 (Cuba, etc.); 1892, p. 28, 62 (Porto Rico, Vieques). MAR- 

 TENS, Biologia Centr. Amer. Moll., p. 293, pi. 17, f. 9 

 (Mexico, etc.). Bulimus subula Pfr., BINNEY, Terr. Moll. 

 U. S. ii, p. 285, pi. 53, f. 4. Bulimus contractus POEY, Me- 

 mories i, p. 205, 212, pi. 26, f. 19-21 (San Diego de los Banos, 

 Cuba). Stenogyra (Opeas) striosa Ad., Henderson, Nautilus 

 viii, p. 20, no. 114 (Jamaica). Opeas dresseli MILLER, Malak. 

 Blatter (n. F.) i, 1879, p. 123, pi. 14, f. 1 (Guayaquil, 

 Ecuador) . 



0. micra is the most widely distributed American Opeas. 

 It was described from Bolivia, near or at the southern extreme 

 of its range. The type figures, copied on pi. 27, fig. 49, are 

 good except in showing the apex too acute, an error commonly 

 made in figuring Opeas. The shell is perforate, and tapers 

 regularly to the very obtuse apex. The first 2 or 2^2 whorls 

 are smooth; then widely spaced thread-like stria; appear in 

 high relief on the weakly striatulate surface, and are usually 

 strongest near the suture above. On the last whorl the striae 

 became less emphatic and closer. This description applies to 

 well-sculptured shells, such as pi. 28, fig. 58 from Honda, 

 Colombia, measuring 6.8 x 2.1 mm., with 7 whorls. Very 

 often the stride are much weaker, almost obsolete except im- 

 mediately below the sutures; and there are, in most lots, in- 

 termediate forms also. Part of the Colombian and Para 

 shells before me are of this sort. 



The Central American shells are similar to Colombian ; but 

 in Yucatan a longer, more slender form prevails, quite like 

 the large Cuban type. One from Izamal measures 8.8 x 2.5 

 mm., with 8 whorls. Most shells in a very large series from 

 San Juan Bautista, Tabasco, are deficient in riblets (pi. 28, 

 fig. 59) . The specimens from the State of Vera Cruz are also 

 rather weakly sculptured. 



In Cuba some diversity is encountered. Some shells, as at 

 Marianao near Havana, are typical. Others (pi. 27, fig. 57), 



