I 0. 



Plate III. 



Io 



Species 16. (Mus. Anthony.) 

 rhombica. Io testa recti fusiformi, fulvo-olivaced, 



purpureo-fusco quadrifasciatd, anfractibus concavo-de- 

 clivibus, medio conspicue angulatis et tuberculalis ; 

 columella parum contortd, canall breviusculd, attenuato- 

 appressd. 



The rhombic Io. Shell striately fusiform, fulvous-olive, 

 encircled with four bands of purple-brown, whorls 

 concavely sloping, conspicuously angled and tuber- 

 cled in the middle ; columella but little twisted, canal 

 rather short, attenuately appressed. 



Anthony, MS. 



Hab. Southern United States. 



The specimens described and figured in this Plate have 

 been kindly forwarded to tne for publication by Mr. An- 

 thony, of Cincinnati, who possesses a most remarkable 

 collection of the genus. " Many of the Melanidm which I 

 send you," he writes me word, " were collected personally 

 by myself in 1853, when I made a pedestrian tour of over 

 six hundred miles in our Southern States, and collected 

 from every stream in my route. Of Ios, my assistant 

 and myself secured eight thousand in all." The speci- 

 men which Mr. Anthony has here named /. rhombica, is 

 of more regular growth than I. spinosa, with less twist in 

 the columella, and the whorls are more concavely sloping. 



Species 17. (Mus. Anthony.) 



Io gibbosa. Io testa obeso-fusiformi, fulvd, anfractibus 

 rude oblique plicatis, medio obtuse tuberculalis, anfractu 

 ultimo inferui spiraliter plicato-costato, costd tumidd, 

 gibbosa ; columella arcuato-contortd, canali late ejfusd. 



The gibbous Io. Shell stoutly fusiform, fulvous, whorls 

 rudely obliquely plicated, obtusely tubercled in the 

 middle, last whorl spirally plicately ribbed round the 

 lower part, rib swollen, gibbous ; columella arcuately 

 twisted, canal broadly effused. 



Anthony, MS. 



Hab. Southern United States. 



The gibbous ridge which encircles the lower portion 

 of the body-whorl of this species, " is not," writes Mr. 

 Anthony, " a mere accidental aberration. I have seen 

 others like it." 



Species 18. (Mus. Anthony.) 



Io recta. Io testa subelongato-fusiformi, recta, sol'dius- 

 culd, fulvo-olivaced, anfractibus cuperne concavo-decli- 

 vibus, ad angulum conspicue tuberculalis, tuberculis 

 parviusculis ; columella arcuato-contortd, canali late 

 appressd, aperturd oblongd, fauce rufo-purpureo linctd 

 et fasciata. 



The straight Io. Shell somewhat elougately fusiform, 

 straight, rather solid, fulvous-olive, whorls concavely 

 sloping round the upper part, conspicuously tubercled 

 at the angle, tubercles rather small ; columella arcu- 

 ately twisted, canal broadly appressed, aperture oblong, 

 interior banded and stained with reddish purple. 



Anthony, MS. 



Hab. Tennessee, United States. 



Having no means of comparison, I give these species 

 solely on the authority of Mr. Anthony. 



Species 19. (Fig. a, b, Mus. Cuming.) 



Io turrita. Io lestd elongalo-lurritd, fusiformi, olivaced, 

 purpureo obscure fasciata, anfractibus numerosis, con- 

 cavo-declivibus, medio validi spinoso-tuberculatis ; colu- 

 mella attenuato-contortd. 



The turreted Io. Shell elongately turreted, fusiform j 

 olive, obscurely banded with purple, whorls numerous, 

 concavely sloping, strongly spinosely tubercled round 

 the middle ; columella attenuately twisted. 



Anthony, Pro. Acad. Nat. Sci. Philadelphia, 1860, p. 69. 



Hab. Tennessee, United States. 



This species seems to possess naturally an elongately 

 turreted growth, although the specimens figured show 

 that it varies in elongation. 



Species 20. (Mus. Anthony.) 



Io lurida. Io testa recti fusiformi, intus extusque lurido- 

 purpured, anfractibus tavibus, inermibus, superni con- 

 cavo-impressis, medio tumido-gibbosis ; columella vix 

 contortd. 



The lurid Io. Shell straightly fusiform, lurid-purple with- 

 in and without, whorls smooth, unarmed, concavely 



April, 1861. 



