28 Moll. 
MOLLUSCA. 
(8) The persistent specific character of some Mollusks and the exces- 
sive evidence of variation in others. 
North America has 832 species of Unio ; 82 of them inhabit the Ohio 
river. The author thinks that the present natural agencies do not suffice 
for explaining this distribution. J. Cincinn. Soc. iii. pp. 317-324. 
Notes on the distribution and varieties of several species of Helix ; id. 
1. c. pp. 33-40. Hyalina milium (Morse) found in Cincinnati ; W. 
Doberty, op. cit. i. [1878] p. 23. 
California. Notes on the geographical occurrence and the gradual 
transitions of several species of Helix by J. G. Cooper, P. Am. Phil. Soc. 
xviii. pp. 282-285. The more important of them will be meniioned in the 
systematic part. 
Bermudas. The known land shells enumerated by Kobelt, JB. mal. 
Ges. vii. pp. 257 & 286. 
14 . Central America and West Indies. 
Mexico. Abstract of Strebel & Pfepper’s paper [Zool. Rec. xvi. 
Moll. p. 29] by the Recorder, JB. mal. Bl. vii. pp. 92-100. 
The Auriculidce and Limnceidce of Mexico and Central America are 
treated by Fischer & Crosse in the 7th (or first of vol. ii.) part of land 
and freshwater Mollusca in the “ Mission scientifique au Mexique.” They 
describe and figure 4 species ot Auriculidce^ ^ of A ncylus, 2 of Limncea^ 
14 of Planorhis, 2 of Planorhula, and figure further 2 species of Aplexa, 
pp. 1-80, pis. xxxii.-xxxvi. 
Kobelt discusses the distribution of the land and freshwater shells in 
the West Indies, and enumerates the known species of each island ; JB. 
mal. Ges. vii. pp. 243-286. 
Hayti and Bahama Islands. Notes on their land shells, with descrip- 
tions of several new species, by D. Weinland, JB. mal. Ges. vii. pp. 
338-378, pi. xii. 
15 . South America. 
Ecuador. Critical notes on Miller’s paper [Zool. Rec. xvi. Moll. p. 29] 
by H. Doiirn, JB. mal. Ges. vii. pp. 83-92. 
Galapagos. The known land shells enumerated by Kobelt, JB. mal. 
Ges. vii. p. 242. 
Peru. 4 new species of Clausilia (Nenia) by Bottger, Nachr. mal. 
Ges. 1880, pp. 111-114. 
Juan Fernandez and Masafuero. The known land shells enumerated 
by Kobelt, JB. mal. Ges. vii. p. 242. They are 24 in number, including 
comparatively many Succinea and no Bulimus ; the genus Tornatcllina 
with 5 species, is rather Polynesian than American. 
Argentine States. Some of Boring’s now species of Odontostomus are 
figured by Kobelt, JB. mal. Ges. vii. pi. ix. 
Boring’s various papers on Argentine land shells, 1874-75, already 
mentioned in the preceding vols. of Zool. Rec., are also published in 
Period. Zool. Argent, i. [1874-75] & ii. [1875]. 
