EASTERN PROVINCE XORTIIERlSf REGION SPECIES. 175 



a depositiou of callus on the parietal wall of the aperture. Greatest 

 diameter, G"^"; altitude, 12""'. 



Succinea Ihieata, W. G. Binney, Proc. Acad. Nat. Sci. Pbila., 1857, 19 ; Proc. Bost. Soc. 

 Nat. Hist., vi, 155 (April, 1857) ; Terr. Moll., iv, :38, pi. Ixxx, fig. 5; L. & Fr.- 

 W. Sh., i, 2(52 (1869) ; Terr. Moll., v, 420, fig. 298.— Tkyon, Am. Jonrn. Concb., 

 ii, 235 (186G). 



Succinea chrysis, West ? see ai>pendix. 



Fort Uuion, Nebr ; also in New Mexico, Arizona, and Sonora, Mexico. 

 Thus it belongs to both the Interior Kegion of the Eastern Province 

 and to the Central Province. 



The specimens collected being dead and eroded, it is impossible to say 

 what is the color of the shell wGen fresh. It is probably ashy-white, 

 resembling the true S. camptstris of the Southern States. The revolving 

 lines, which distinguish it, are most apparent on the middle of the body- 

 whorl. These are quite coarse and placed at irregular intervals, on 

 some specimens scarcely discernible. The aperture is unlike that of any 

 other of our species ; bi.'iiig correctly egg-shaped, it is nearest in form 

 to that of 8. oampestris, but is less expanded. The parietal wall of 

 the aperture is unusually horizontal. In general aspect it resembles 

 somewhat 8. vermeta, bnt is distinguished from that shell by its more 

 oval shape and the greater convexity of the whorls. It is the heaviest 

 American species. 



This species must not be confounded with >S'. Uneata, De Kay. 



Jaw as usual; no anterior ribs. 



The lingual membrane (Terr. Moll., V, Plate X, Fig. L) has 26-1-26 

 teelh, with 4 perfect laterals, but the transition to marginals is very 

 gradual. The teeth have a very broad base of attachment, and very 

 slender, sharp cutting points. 



d. Eastern Province — Species of the IS'orthern Eegion. 



(See p. 26.) 



It m\ist be borne in mind that the universally distributed species 

 (p. 60) are found in this region also. 



Family LTMACID^. 



VITRIJVA, Drap. 



Anim'al heliciform, obtuse before, pointed behind. Mantle posterior, 

 with an anterior prolongation covering the back, and with a process or 

 prolongation which is reflected backward upon the shell. A distinct 



