10.— Plate II. 



The bee-hive Io. Shell conoid, solid, olive, whorls 

 eight, convexly sloping, the first obliquely rudely pli- 

 cated, the rest smooth, last whorl sometimes plicately 

 noduled at the upper part, angled at the lower, no- 

 duled at the angle, then conspicuously spirally ridged ; 

 aperture small, columella short, slightly twistedly 

 channelled. 



Melania alveare, Conrad. 



Melania pernodosa, Lea. 



Hab. Tennessee, United States. 



The chief peculiarity of this species, which is of a parti- 

 cularly solid conical form, consists in the base being con- 

 spicuously circularly ridged whilst the rest of the shell 

 is smooth. 



Species 13. (Mus. Cuming.) 



Io rota. Io testa ghboso-turritd, crassd, ponderosd,fla- 

 vescente-olivaced, ad basin fitsco nnifasciatd, anfrac- 

 tibus panels rude concavo-declivibus, substriatis, tuber- 

 culis grandibus oblique compressis ad peripJieriam 

 cinctis ; columella brevi, parum contortd. 



The water-wheel Io. Shell globosely turreted, thick, 

 ponderous, yellowish, encircled at the base by a brown 

 band, olive, whorls few, rudely concavely sloping, 

 faintly striated, encircled round the periphery with 

 large obliquely compressed tubercles ; columella short, 

 but little twisted. 



Hab. United States. 



A solid globosely turreted shell, prominently armed 

 with tubercles, which are compressed obliquely into fans, 

 like the fans of a water-wheel. 



Species 14. (Fig. a, b, Mus. Cuming.) 



Io fasciolata. Io testa abbreviato-fusiformi, Jlavescente- 

 viridi, fasciis angustis olivaceis cinctd, anfractibus 

 quinque ad sex, convexo-declivibus, primis lavibus, ul- 

 timo gibboso-angulato, ad peripheriam tuberculato, tu- 

 bercidis distantibus ; aperturd trapeziformi, vix cana- 

 liculatd. 



The banded Io. Shell shortly fusiform, yellowish-green, 

 encircled with narrow bands of olive, whorls five to 

 six, convexly sloping, the first smooth, the last gib- 

 bously angled, tubercled at the periphery, tubercles 

 distant ; aperture diamond-shaped, scarcely chan- 

 nelled. 



Hab. United States. 



Closely allied to I. Duttoniana, but less channelled, and 

 more widely apertured, owing to the more gibbously 

 angled circumference of the last whorl. 



Species 15. (Mus. Cuming.) 



Io robulina. Io testa obtuse fusiformi, virescente-oliva- 

 ced, purpurea fasciatd, anfraclibus quinque ad sex, su- 

 pra et infra angulatis, ad angulos valide rude tubercu- 

 latis ; columella (enuiter products, subcontortd. 



The oak Io. Shell obtusely fusiform, greenish-olive, 

 banded with purple, whorls five to six, angled above 

 and below, strongly rudely tubercled on each angle ; 

 columella thinly produced, slightly twisted. 



Anthony, MS. in Mus. Cuming. 



Hab. Tennessee, United States. 



The most elongately channelled of this group of the 

 genus, and the nearest approach in it to the typical form. 



