gibbons: on W, INDIAN PULMONIFERA. 133 



to Adams' description and figure of Z. umbilicata ; on the 

 other hand they correspond exactly with the typical figure of 

 L. Jmmilis, Say (N. Amer. L. and F. W. Shells, fig. 99, p. ()-^^ 

 and with the description, except that they have 5 instead of 

 "nearly 6 whorls." I have specimens of Z. htimilis from several 

 localities in the United States, but apparently none perfectly 

 typical — at least they do not agree with the figurequoted above, 

 and consequently differ from the Cuban mollusc. I see no 

 difficulty in considering Z. Cubensis a variety of Z. truncatnia, 

 Miill, of which Jeffreys .says Z. humilis is a synonym and 

 L. umbilicata an alhed species (Ann. and Mag. N. H., 1872, 

 p. 246). 



Physa Sowerbyana?, D'Orb. (=? P. ventricosa, Guild.) Vera 

 Cruz, Habana, and St. Thomas. The Mexican shells are 

 a trifle smaller and lighter in color than those from St. 

 Thomas. 



Planorbis Havanensis, Pfr. Georgetown. In Mr. Guppy's 

 hst of Trinidad shells, this is mentioned (under the name of 

 P. Terverianus, D'Orb.) as occurring in that island and the 

 Antilles only. 



Planorbis turn id us, Pfr. Jamaica and Vera Cruz. The shells 

 agree with description and figure of the above in L. &= F. W. 

 Shells N. Amer., ii., p. 105. C. B. Adams described the 

 Jamaica shells under the name of Planorbis affinis. 



Megalomastoma Antillarum, Sow. St. Thomas. This species 

 resembles CydopJwriis Wahlbergi, Bens., a Natal shell, in 

 habits, preferring to hide itself among damp mould, under 

 dead leaves, in the darkest parts of woods. In both 

 species the epidermis is usually very thick, and readily 

 peels off when dry. Shells are however sometimes to be 

 found where the ground is somewhat bare and stony ; the 

 epidermis is then much thinner, smoother, and lighter in 

 color. 



