90 



LAND AND FRESH- WATER SHELLS OF N. A. f PART III. 



Fig. 177. 



(1«44) ; Arch. f. Nat. 1843, II, 130; Annals Nat. Hist. X, 83, pi. 



vi, f. 8. 

 ?Leptoxis nuttulliana, Haldeman, Mon. Lept. 6, pi. v, f. 15(3 (1847?). 

 Ancnlotus nutiallii, Reeve, Con. Icon. 46 (18G1) (excl. syn. A.fuscus). 

 Bilhi/iiia f<ei/:inulis, Carpenter, Brit. Ass. Ad. Sc. 1857, 32*3, no descr. 

 Amnicola seininalis, Cooper, P. R. R. Rep. XII, 374 (1859), no descr. 

 Amnicola hindsi, Baird, Pr. Zool. Soc. Lond. 1863, 67. 



A very common species through Oregon and California. It 

 was originally described and figured (as copied above) under the 

 name of Paladina, and has since been referred to the genera 

 Amnicola, Bilhijuia, and Leptoxis. Its outward 

 features are most closely allied to those of the last 

 mentioned genus. I should have considered it 

 a Leptoxis had not Dr. Stimpson discovered its true 

 characters. From the other genei*a to which it has 

 been referred it is readily distinguished by its horny 

 subspiral operculum and thick shell. 



I have seen no authentic specimen of Paludina 

 seminalis, but have no doubt of No. 9212 and 9213 

 of the collection being referable to it. The origi- 

 nal description and figure are copied below. It is from them I 

 am induced to place it in the synonymy of nuttalliana, as done by 

 Haldeman. 



Fig. 178. Paludina seminalis, Hinds. — Shell obtusely turreted, solid, 



horn colored, smooth ; apex eroded ; whirls 4 ; aperture bluish, 

 expanded. 



River Sacramento, California. 



Distinguished from P. nurha, Lea, which is from a neigh- 

 boring locality, by its somewhat smaller size, blui.sh instead 

 of white mouth, having one whirl less, the aperture more 

 expanded, and absence of the black lines round the mouth, which when 

 present is so good a character in his .shell, but which, in any numerous 

 specimens of it, I do not find at all constant, and usually only to be seen 

 in those better developed. Anodon angulatus is also found abundant in 

 this river, &c. {Uinds.) 



I have not seen an authentic specimen of Amnicola hindsi. 

 By the kindness of Mr. Carpenter I am able to give a translation 

 of the original description and copy of the original figures. The 

 latter will be published in the Report of the British N. A. Boun- 

 dary Commission. The species seems to me identical ^Yith Flu- 

 minicola n'dlalliana. 



