176 AMERICAN JOURNAL 



A. pyramidalis, New Zealand. A. monilifera, Swan River. 

 " contusa. " hulloides. 



" marmorata. " oryza. 



" sarda. " fasciata. 



Unio (Aug. — Nov., 1864,) comprises, as far as published, 

 over eighty species, most of which are American. The figures 

 are not executed with that fidelity which usually distinguishes 

 the pencil of Mr. Sowerby. The wrong valve is selected for 

 figuring, and the shells, consequently, appear badly on the 

 plates. No attention has been paid to delineating the undula- 

 tions of the beaks, (actually the 7)1081 constant of specific cha- 

 racters,) a feature which seems to be generally overlooked by 

 European naturalists; nor is a fair idea of the convexity of 

 the valves conveyed by these drawings. In species like mul- 

 tiplicatus, the tuberculated surface is made by far too promi- 

 nent, and the tubercles themselves are too large. The color- 

 ing is a perfect success. 



We regard it as a great misfortune that Mr. Reeve has seen 

 fit to adopt the very uncertain names of Rafinesque for many 

 of the species. As the completion of the monograph will 

 still require a considerable time, we hope he will ignore these 

 names for the future. 



Unio ceelatus (pi. 2,) is figured from a poor specimen of the 

 species. The same may be said of U. trapezoides, (pi. 5.) 



U. ajnculatus (pi. 3, fig. 11) is not covered by a series of 

 vaulted scales, as depicted in the figure. 



We do not recognize U. PhilUpsii^ Conrad, in the figure, 

 (pi. 4, fig. 15,) given for that species. 



U. Elliottii (pi. 5, fig. 20) is figured from a miserable speci- 

 men, and is not at all characteristic. 



U. quadratus, Raf, (pi. 6, fig. 24,) is certainly 7ioi U. asper- 

 rimus, Lea, but U. lachrymosus, Lea. What U. quadratii.^ 

 really is we cannot tell. 



The "hump" on U. dromas (pi. 8, fig. 29) is not depicted, 

 and U. cicairicosus (same pi., fig. 31,) is from a very poor 

 specimen. 



U. nodulosus (pi. 9, fig. 32) is not Mya nodulosa, Wood, which 

 is a Prisodon,^ but more like to, if it does not = U. Leai, 

 Gray. 



U. graniferiLS (pi. 9, fig. 34) is from a poor, half-grown spe- 

 cimen. 



U. lachrymosus (pi. 9, fig. 33) is U. asperrimu^. 



U. Perlensis (pL 11, fig. 42,) Con. — We spell it Pearlensis. 



* Vide Isaac Lea in Proc, Acad. Nat. Sci., Philadelphia, Vol. 6, 1853, p. 

 368. 



