PLANORBIS, 391 
Planorbis haldemani, Dunker, in Martini & Chemnitz, Syst. Conch.-Cab. ed. 2, Limnzaceen, p. 59; 
t. 10. figg. 38-40 (1850); Binney, Land and Freshw. Shells of N. Am. ii. p. 110, fig. 185 
(copied from Dunker)*; vy. Mart. in Malak. Blitt. xii. p- 56 (1865) °; Strebel, Beitr. Mex. 
Land- und Siissw.-Conch. i. p. 44, t. 5. fig. 22°° (nec P. haldemani, C. B. Adams, from 
Jamaica, 1849). 
Planorbis liebmanni, Dunker, loc. cit. p. 59, t. 10. figg. 32-34 (young); Binney, loc. cit. p. 108, 
fig. 183 (copied from Dunker) ”; Fisch. & Crosse, loc. cit. p. 71%. 
Planorbis depressus, Uhde, in litt.™. | 
Planorbis micromphalus (Dunker), Strebel, loc. cit. p. 47”. 
Hab. Centra, Mexico: near the city of Mexico (Liebmann 7 8); Mexico, without 
nearer indication of locality 1 1, 
S. CentraL Mexico: San Carlos, east of Oaxaca (Hége). 
E. Mexico: Vera Cruz (Liebmann 113; Uhde® 4; Strebel 10; Hoge); San Juan, 
near Vera Cruz (Heilprin ®), 
S.E. Mexico: Balancan, near San Juan Bautista, State of Tabasco (Morelet 4), 
Yucatan: La Palizada, on the frontier of Tabasco (Morelet 24); Laguna de Terminos 
(Berendt °); Carmen Island, in the entrance to this lagoon (Morelet 4). 
In some specimens of this species the penultimate whorl on the left side is in the 
same level with the last, in others somewhat excavated. I have not seen an example 
with the aperture so distinctly enlarged and expanded (like that of P. campanulatus) 
as it is described and figured by Dunker’ ; this may be an individual variation. 
P. havanensis, Pfr., from Cuba, comes near P. orbiculus; but it is a little less 
compressed, and the left side is more excavated, with the visible part of the penul- 
timate whorl comparatively smaller, 
There is a similar shell in the Berlin Museum, from Diquis, below Terraba, Costa 
Rica; but it is too imperfect for identification, and is only mentioned here to record 
the presence of the subgenus Menetus in Costa Rica. 
P. orbiculatus (“ Morelet”), Sowerby, in Reeve’s Conch. Icon. xx., Planorbis, t. 3. 
fig. 22, seems to belong to a different species. 
7. Planorbis nicaraguanus. (Tab. XXI. fig. 10.) 
Planorbis nicaraguanus, Morelet, Test. Noviss. ii. p. 14 (1851) *. 
? Planorbis nicaraguanus, Clessin, in Martini & Chemnitz, Syst. Conch.-Cab., Limnziden, p. 207, 
t. 31. fig. 10. 
? Planorbis tumidus (Pfr.), Tate, Am. Journ. Conch. v. p. 158 (1870) °. 
Hab. Centrat Nicaragua: Lake of Nicaragua (Morelet1?, Tate*); Rio San Juan 
(Tate *). 
I am indebted to Mr. E. A. Smith for a sketch of a typical specimen from Morelet’s 
collection, now in the British Museum (fig. 10). He informs me that the greater 
