22 LAND AND FRESH-WATER SHELLS OF N. A. [PART IV. 



Observations.— This species is much more inflated, and has more 

 numerous tubercles than A. Duttoniana, Lea; it is in appearance 

 more like an obese variety of A. verrucosa, Raf., but that species is 

 heavier in texture, and has several rows of tubercles. The well- 

 developed tubercles and iuferiorlj' contracted aperture will readily 

 distinguish this species from Lithasia fidiginosa, Lea.— Tr>jon. 



10. A. stygia, Say. 



Melania styffia, SAY„New narmony Dissem., p. 201. An?. 28. 1829; reprint, p. 17. 



Bi.N'NEV's Reprint, p. 142. Bixney, Check List, No. 2:)1. Whkatley, Cat. 



Sliells U. S., p. 27. Jay, Cat., 4th edit., p. 275. DeKak, Moll. N. Y., p. 93. 



Reeve, Monog. Mel., sp. 400. Brot, List, p. 40. 

 Melania tuberculata, Lea, Philos. Trans., iv, p. 101, t. LI, f. 31. Obs., r, p. 111. 



DeKay, Moll. N. Y.. p. 93. Wheatley, Cat. Shells V. S., p. 27. BixNEY, Check 



List, No. 277. Jay, Cat., 4th edit., p. 27.5. Catlow, Couch. Nonieuc, p. 189. 

 Jtif/n tuberculata, tea, Chexu, Man-..Concliyl., i, f. 2U17.. 

 M<l(u\ia Spixiana, Lea, Philos. Trans., vi, p. 93. Obs., v, p. 93. 

 Mchniin voduta. REEVE, Monog. Jlel., fig. 422. 

 lo tuberculata, Adams, Genera, i, 299. 



Description. — Shell robust, ovate conic, black ; spire rather larger 



than the aperture, eroded at tip; volutions five, hardly^ convex; 



wrinkles obsolete, excepting a few larger ones ; suture not profoundly 



indented; aperture narrowed at base into a slight sinus and suban- 



gulated ; much wider- in the middle ; labrum much ar- 

 Fig. 57. 



cuated in the middle. 



Greatest breadth, less than half an inch, length, three- 

 fourths. 



Observations.^- A specimen of this shell was given to 

 me by Mr. Lesueur; several were found in Cumberland 

 River by Dr. Troost. In form il resembles armigera, nob., 

 more than any other species, but that shell is armed with 

 tubercles and ornamented: by colored lines, its suture also is only 

 a simple line. — Say. 



The following is Mr. Lea's, descriptioa of 



lo tuberculata. — Shell obtusely turreted, wide, very dark brown or 

 black; apex obtuse ; whorls, five ; middle of the last whorl furnished 

 with tubercles ; outer lip irregularly curved; base angalatod ; aperture 

 purple and one-half the length of the shell. 



Habitat. — Tennessee River; Prof. Vanuxem. 



Diameter, -5; length, -Oof an inch. 



Observations. — This species is. somewhat allied to the 31. armigtra 



