PHOTOGRAPHIC CONCHOLOGY. 
The final numerals indicate thfe average size of the species, the photographs of which 
will henceforth be less reduced. The specimens are in Mr. Hanley's Collection. 
PLATE I. ANODONTA, (chiefly). 
1 A. Vignouana, Bernar. Joum. Cone. vii. p. 302, pi. 10, £ 1, as Margaritiana V. 
— 2 inches. 
2 A. ferruginea, Lea, Trans. Amer. Phil. ser. 2. viii. pi. 19, f. 43.— If. 
3 A. subcrassa, Lea, Proc. Zool. Soc. 1850, p. 198. — 21. 
4 A. Californiensis, Lea, Trans. Amer. Phil. ser. 2, x. p. 42, pi. 25, f. 47.-2. 
5 A. Perussacciana, Lea, Trans. Amer. PhU. ser. 2. v. p. 45, pi. 6, f. 15.— 2J. 
6 A. Cumingii, var. Lea, Proc. Zool. Soc. 1850, p. 199 ; named from his type in 
Cuming's collection. — 2J. 
7 A. obtusa, Spix, Testae. Brasil. pi. 22, £ 3, 4. — 2. 
8 A. tenuis. Lea, Proc. Zool. Soc. 1850, p. 198.— 2. 
9 A. pavonia. Lea, Trans. Amer. Phil. ser. 2, vi. p. 78, pi. 21, £ 65.— 2|. 
10 Unio nux-Persica, Dunker, Zeitschr. Malak 1848, p. 182.-1. 
PLATE 11. UNIO (continued) 
1 TJ. Menziesii, Gray, Appx. Dieffenb. N. Zeal.— 
2 TJ. Eorbesianus, Lea, Trans. Amer. Phil. ser. 2, x. pi. 16, £ 17.— If. 
3 TJ. persulcatus, Lea, Observ, TJnio (Jour. Ac. ISTat. Philad. ser. 2.) vii.— 2. 
4 TJ. decurvatus, Eossmas. Icon. Land u. Suss. Moll. pi. 2, p. 22, £ 131.— 21. 
5 TJ, Oregonensis, Lea, Trans. Amer. Phil. ser. 2, x. p. 31, pi. 22, £ 32.-2. 
6 TJ. Edgarianus, var. Lea, Trans. Amer. Phil. ser. 2, viii. pi. 15, £ 30.— If. 
7 TJ. Eousii, Dupuy, Moll. France, pi. 28, £ 18 (TJ. Eequienii. var. of the letterpress). 
—3. 
8 TJ. Powellii, Lea, Trans. Amer. Phil. ser. 2, x. pi. 19, £ 25.-3. 
9 TJ. "trirostris. Hindostan," In 1858, Lea returned me this species as new to him : 
it had long been thus named (I know not by whom) in my collection. Had not 
Mr. Benson formerly regarded it as a variety of corrugatus, I should have taken 
for it a species named by himself. — 2. 
10 TJ. Prevostianus, Lea, Trans. Amer, Phil. ser. 2, viii. pi. 19, £ 24.-21. 
