— 149 — 
Vo. IV. — Observations, etc... 
Philadelphia : | Printed for the Author. gr. in-4°, 1848, 
101 p. avec 13 planches. 
Ce volume est formé de la réunion des trois articles 
suivants : 
A). Continuation of Mr. Lea’s Paper on Fresh Water 
and Land Shells. 
Transactions American Philosophical Society; IX; 
5 Avril 1844, p. 1 -31. | 
B). Description of New Fresh Water and Land Shells. 
Loc. supra cit.;1X, 1845, p. 275-282; pl. XXXIX-XLII. 
C). Description of New Fresh Water and Land Shells. 
Loc. supra cit.; X, 7 Janvier 1848, p. 67-101, pl. 1-IX. 
Vo. V. — Observations, etc... 
Philadelphia : | Printed for the Author. gr. in-4°; 1852, 
p. 62 et 19 planches. 
Ce volume est formé de la réunion des articles suivants : 
A). Descriptions of New Species of the Family Unionidæ. 
Transactions American Philosophical Society; New 
Series, X, 5 mars 1852, p. 253-294, pl. XII - XXIX. 
B). Description of a New Genus (Basistoma) of the 
Family Melaniana, together with some New Species of 
American Melaniæ. 
Loc. supra cit.; X, 5 mars 1852, p. 295-302, pl. XXX. 
C). Description of a New Species of Helix, from Cali- 
fornia, and a new Characteristic form of certain American 
Colimaceæ. 
Loc. supra cit.; X, 5 Mars 1852, p. 303 - 305. 
Voz. VI. — Observations | on | the | Genus Unio, | together 
with | Descriptions of New Species, their Soft Parts, and 
Embryonie Forms, in | the Family Unionidæ. 
Philadelphia : | Printed for the Author. gr. in-4°, 1858, 
p. 97 avec 29 planches. 
