Notices respecting New Books. 377 



7. Unio ater. — Testd ovatd, incequilaterali^ transversa, ventrico- 

 sissimd ; umbonibus elevatis ; natibus prominulis ; epidermide rugosd 

 nigrdque; umbonibus elevatis; dentibus cardinalibus erectis, cristatis, 

 lateralibus granulatis, rectisque ; margaritd rosed. 



Hab. Mississippi below Natchez. T. W. Robeson. My cabinet. 

 Cabinet of Prof. Vanuxem. Diam. 2 - G, length 3, breadth 4 - 5 inches. 



8. Unio rcbiginosus. — Testd inceqiiilaterali, transversd, postice 

 sub-biangulari, antice rotundatd; valvulis sub-crassis ; natibus pro- 

 minentibus, recurvis, postice sub-angulatis ; dente cardinali magno, 

 laterali ciasso ; margaritd salmonis colore. 



Hab. Ohio. My cabinet. Cabinet of T. G. Lea. Cabinet of Prof. 

 Vanuxem. Cabinet of the Academy of Natural Sciences. Diam. 1*2, 

 length 2*1, breadth 2-6 inches. 



9. Unio Heterodon. — Testd rhomboido-ovatd, incBquilaterali, ven- 

 tricosd; valvulis tenuibus ; dentibus cardinalibus compressis, latis ; 

 dentibus lateralibus sub-curvatis, dente laterali valvule dextrce, duplici; 

 natibus prominentibus ; ligamento sub-brevi; margaritd albd. 



Hab. Schuylkill and Derby Creek, Pa. My cabinet. Cabinet of 

 Mr. Mason. Cabinet of Prof. Vanuxem. Cabinet of Dr. Griffith. 

 Cabinet of the Academy of Natural Sciences. Cabinet of Mr. Hyde. 

 Cabinet of Mr. Phillips. Cabinet of Mr. Conrad. Diam. '5, length "9, 

 breadth 1*5 inch. 



10. Unio sulcatus. — Testd sub-ellipticd, inceqiiilaterali, ventricosd, 

 sub-emarginatd ; valvulis crassis ; natibus fere terminalibus ; dentibus 

 cardinalibus lateralibusque magnis, et duplicibus in valvulis ambabus ; 

 margaritd purpured. 



Hab. Ohio. T. G. Lea. My cabinet. Cabinet of T. G. Lea. 

 Cabinet of Prof. Vanuxem. Cabinet of P. H. Nicklin. Cabinet of the 

 Academy of Natural Sciences. Diam. 1-3, length 1*7, breadth 2*3 

 inches. 



11. Unio planulatus. — Testd incequilaterali, ovato -ellipticd, trans- 

 versd ; complanatd per umboms a natibus usque ad marginem inferi- 

 orem, maculis quadratis radiatim pictd ; natibus prominulis ; dente car- 

 dinali parvo, laterali magno, crasso, curvato ; margaritd sub-cceruleo- 

 albd. 



Hab. Ohio. T. G. Lea. My cabinet. Cabinet of T. G. Lea. Ca- 



subject to certain variations, but permanent within fixed limits, seems to me 

 the most rational opinion, although some of our most judicious naturalists 

 think otherwise. Your account of the animal of the U. irroratus affords a 

 strong argument in favour of this belief; for it proves that to be, beyond 

 doubt, as distinct a species as any in any class of animals. Yet this may 

 always be known with certainty by the shell, which, though so well charac- 

 terized, is not, however, more different from the rest of the genus, than they 

 are from each other, and frequently still less so. If, therefore, this difference 

 is found to be constantly indicative of a species in one instance, it must also 

 be in others. I believe that our lakes and rivers contained the same form of 

 shells at the creation and ever since that they do at this day. If they are 

 hermaphrodite per se, as is said of them, it could not be otherwise ; and if 

 the contrary were admitted, natural history would not deserve the name of 

 a science." 



N. S. Vol. 8. No. 47. Nov. 1830. 3 C binet 



