EASTERN PROVINCE — INTERIOR REGION SPECIES. 2J5 



mark, which was made by Say in his original descrij)tion, is entirely 

 inapplicable to the specimens which are usually known as Z. gularis. 

 It also resembles Z. suppressus, Say, the next-described species, with 

 which it has long been confounded. But it has at least one more whorl, 

 the spire is much higher, the nucleus of the shell is smaller, so that 

 the first two whorls are finer and more delicate, and the base is not so 

 convex. The base of the shell is exceedingly like that of Z. internus. 



It is the totality of the characters which makes up the species, for 

 iudividuals differ considerably in the height of the spire, the size of the 

 umbilicus, and in the degree of prominence of the teeth. One tooth is 

 often wanting, sometimes both. 



The deposition of testaceous matter thickening the shell at its aper- 

 ture occupies about one-fourth of the base, through which it is seen. 

 The character of the lamellar folds, within the aperture, resembles 

 those of Sagda epistyliuni, Mliller, in which species they are large and 

 I)rominent. 



Jaw highly arcuate, ends attenuated, anterior surface smooth, cut- 

 ting edge with a well- developed median projection. 



The lingual membrane (Terr. Moll., V, Plate III, Fig. K) has 30-1-30 

 teeth, with 10 perfect laterals. 



The genitalia have the two accessory glands to the dart sac, as in 

 intertextus, while suppressus has but one. 



Zonites suppressus, Say. 



Shell convex-depressed, thin, pellucid; epidermis polished, yellowish 

 horn-color ; spire flat ; whorls 6, with crowded, minute, oblique striae ; 

 suture impressed, distinct ; aperture transverse, not ex- ^n, 241. 



panded ; peristome simple, thin at its edge, thickened 

 within ; base rather convex, near the aperture opaque, 

 yellowish- white ; umbilicus small but rounded and dis- ^onites suppressus. 

 tiuct in young shells, obsolete or hardly apparent in older ones ; within 

 the i^eristome are 1 or 2 lamelliform, elongated, oblique teeth. Greater 

 diameter 5, lesser 4'"™; height, 2'""'. 



Helix 8uj)pressa, Say, New Harm. Diss., ii, 229 (1829) ; Descr., 14 ; Binney's ed., 36. — 

 BiNXEY, Bost. Journ. Nat. Hist., iii, 410, pi. xi, fig. 3; Terr. Moll., ii, 253, pi. 

 xxxvii, fig. 1.— De Kay, N. Y. Moll., 38, pi. iii, fig. 24 (1843).— Reeve, Con. 

 Icon., 723.— W. G. Binney, Terr. Moll., iv, 122.— Morse, Amer. Nat., i, 411 

 fig. 25 (1867).— Pfeiffer, Mod. Hel. Viv., iv, 153,— i,EiDY, Anat. Terr. Moll., 

 i, pi. xii, fig. viii. 



1749~Bull. 28 15 



