UNIO.— Plate LXXI 



vellow, which usually deepens in front to blackish- 

 liroivn, not rayed, somewhat compressed at the very 

 sliort and rounded anterior extremity ; ventral margin 

 mucli arcuated ; beaks remarkably prominent, curv- 

 ing forward, nacre purple, cardinal teeth peculiarly 

 large, jagged, pyramidal. 



Laiiakck, Anim. sans Vert. vol. vi. pt. 1. p. li ; Con- 

 rad, Mon. U. p. 19. pi. 8. 

 U. torn/, Eafin. Ann. Sc. Phys. 

 U. obttmi, (Desh. ? in) Cuvier, lu'gne Anim., teste 

 Lea. 



Hah. Western States, North America. 



The valves are moderately large, and are only rayed, if 

 at all, by a few obscure lines upon the swollen nmbonal 

 I'egion ; the hinge-margin is very broad. 



Species 364. (Mus. Hanley.) 



Jxrc) SrcuLUs. Un. tenia elongato-ohlonga, satis coii- 

 vfixd, 7utide luteo-ol'maced, postice productd et squalide 

 viridt, liaud radiatd, suhlmvigatd ; margine veutrali 

 rduso ; nutibm aciiiis, satis eminentihus, serie dupUci 

 porcorum (ijua angulos valde ohtusos juncturd for- 

 muut) subiransversim ornatis; lunula inconspicud, 

 marc/aritd alhido-crenilescenle, dentihm cardinalibus 

 transvn'sl-i. 

 iiE Sicilian Unio. Shell elongated-oblong, mode- 

 rately convex, shining olivaceous yellow, changing 

 to dirty green near the posterior termination, not 

 rayed, nearly smooth ; ventral margin indented ; 

 beaks acute, rather prominent, adorned with two sets 

 of coarse and somewhat transverse raised wrinkles, 

 which meet at a very obtuse angle; lunule incon- 

 .■^picuous, nacre bluish-white, cardinal teeth trans- 



SwAixsoN, Tr. Mahicol. p. 2S2. f 58. 



Vnio TtiHoni, Payrandeau f 

 Hah. Sicily, etc. 



Should this prove the Tuiionl of Payrandeau, that 

 name must take priority. It is certainly quite clisiiia-t 

 from piclorum. The valves are rather strong, not large, 

 and inclined to be reniform, narrow and rounded at their 

 anterior extremity, and produced posteriorly ; the hinder 

 dorsal edsre is sliirhtlv elevated. 



Species 365. (Mus. Hanley.) 

 Unio bilineatus. Uu. Icstd vblcngd, lenui, lavi, modice 

 comicxd, viarginem versus oUvuced, ad umbones ferru- 

 giited, viiuime radiatd, porcis geminis linearibna in et 

 supra casta in umbonalem inconspicuam ornatd ; mar- 

 gine dorsali subrecto ; margine ventrali convexo ; ria- 

 tibiis /laud emineHtihus, Iwiuld nulla, niargaritd al- 

 hidd, deiitibus cardinalibus laiiiiiiatis. 

 The two-lined Unio. Shell oblong, thin, smooth, 

 glossy, moderately convex, ferruginous on the nm- 

 bonal region, changing to olive elsewhere, not rayed, 

 with two closely adjacent linear ridges upon and 

 beyond the inconspicuous umbonal ridge ; dorsal 

 edges nearly straight ; ventral margin convex ; beaks 

 not raised, no lunule, nacre whitish, cardinal teeth 

 lamellar. 

 Lea, Obs. on Unio, vol. i. p. lOS. pi. 11. p. 19. 

 Hall. Hivcr Hoogly, Hindostan. 



In this species, which rarely attains to any considerable 

 magnitude, the linear ridges are only apparent near the 

 umboes, the anterior side, which is not particularly short, 

 is angnlated above and rounded below, and the posterior 

 extremity rotundately subbiangulated. The nacre lias 

 occasionallv a slislit tinge of salmon-colour. 



