NATURAL SCIENCES OP PHILADELPHIA. 398 



tice paulispercrassioribus ; natibus prominentibus, tumidis, incurvis, ad apices 

 vix undulatis ; epidermide luteola, radiis viridis vestitis ; dentibus cardinalibus 

 subgrandibus, erectis corrugatisque; lateralibus crassis, curtis, corrugatis sub- 

 rectisque ; margarita argentea et paulisper iridescente. 



J{ab. Wabash River, New Harmony, Indiana. James Sampson. 



Unio vestitus. Testa, laevi, elliptica, compressa, inaequilaterali, postice ob- 

 tuse angulata, antice rotunda; valvulis subtenuibus, antice paulisper crassiori- 

 bus ; natibus prominnlis; epidermide vel lutea. vel luteo-fusca. polita, radiis 

 obliquis viridis vestitis ; dentibus cardinalibus parvis, compressis, acuminatis, 

 crenulatis, in utroque valvulo duplicibus; lateralibus sublongis, lamellatis, 

 subobliquis corrugatisque; margarita albida et splendide iridescente. 



Hab. Ogecbee River, Georgia. Major Le Conte and J. G. Anthony. 



Descriptions of Seven New Species of the Genus 10. 



BY ISAAC LEA. 



When I proposed in 1831* to form the new genus To for Mr. Say's Fusus 

 ftuviatilis, there were no other allied species known to naturalists. I then pro- 

 posed also to change the specific name to fusiformis, as being more appropriate, 

 and I gave a figure under this name. At that time the canons of nomenclature 

 were not so well understood nor so strict as they have since been ; and it is 

 only justice to Mr. Say to relinquish my specific name, and to replace his. Sub- 

 sequently in 1834, I proposed a new species under the name of Io spinosa, 

 (Trans. Am. Phil. Soc, vol. v. pi. 19, fig. 79.) More recently Mr. Anthony, in 

 the Proceedings of the Academy, (I860,) proposed four new species ; three of 

 which I think belong to the two previously established species. Mr. Lovell 

 Reeve, in his beautiful " Conchologia Iconica," has recently issued among his 

 monographs one of tho genus lo with numerous plates and full descriptions. 

 In this he has introduced a number of species, most of which I think more ap- 

 propriately belong to Prof. Haldeman's genus Lithasia the species of which 

 form a very excellent group, which he separated from Melania and Anculosa 

 but which Mr. Reeve does not seem to recognise. Of the true Io I also think 

 he has considered several varieties as species. 



Io nodosa. Testa tuberculata, elevato-conica, virido-cornea, vittata; spira, 

 regulariter conica; suturis valde impressis ; anfractibus instar denis, planula- 

 tis, medio tuberculatis, infia striatis; apertura pirviuscula, rhomboidea, intus 

 vittata; labro acuto et sigmoideo ; columella alba et valde contorta; canali bre- 

 viuscula.. 



Hab. Tennessee River, Alabama? f Wm. Spillman, M. D. 



Io robosta. Testa, canaliculata, paulisper tuberculata, elevato-conica, pal- 

 lido-cornea, infra obsolete vittata; spira regulariter conica; suturis valde im- 

 pressis; anfractibus instar denis, apud apicem planulatis, infra canaliculata ; 

 apertura parviuscula, rhomboidea, iutus vittata; labro acuto et sigmoideo ; co- 

 lumella, pallido-salmonia; canali breviuscula. 



Hab. Tennessee River, Alabama? Wm. Spillman, M. D. 



Io variabilis. Testa, lasvi, elevato-conoidea, subfusiformi, vel vittata vel in- 

 tense purpurea vel virente ; spira regulariter conoidea ; suturis leviter im- 

 pressis; anfractibus instar novenis, planulatis, in medio angulatis ; apertura. 

 elongato-rhomboidea ; labro acuto et sinuoso ; columella vel albida vel purpu- 

 rea et valde contorta; canali attenuato-constricta. 



Hab. Tennessee River, Alabama? Win. Spillman, M. D. 



* Trans. Araer. Phil. JSoc, January, 1831. 



t Dr. Spillman simply gave Tennessee River as the habitat of these species, but did 

 not mention what part. They are probably from Alabama. 



1861.] 



