EASTERN PROVINCE — INTERIOR REGION SPECIES. 



199 



more fragile shell, proportionally more veiitricose in form, with a shorter 

 spire and larger aperture ; it has a decided green color, almost un- 

 shaded with yellow, while in 8. ohliqua the amber-yellow predominates. 



Fig. 208. 



Lingual mombrane of S. Totteniana. (Morse.) 



By Gwyn Jeffreys referred to S. putris var. (Ann. Mag. Nat. Hist., 

 1872). 



Jaw arcuate, ends blunt; anterior surface with three heavy ribs, 

 modifying the concave and convex margins. 



The lingual membrane is said by Morse, whose figure is given above, 

 lo have 100 rows of 33-1-33 teeth. The bases of attachment are very 

 narrow, and have a peculiar expansion at their lower inner angles. 



e. Species of the Interior Eegion. 



It must be remembered that the universally distributed species are 

 also found in this region. (See p. GO.) 



Family SELENITID^. 



]?IA€ROCY€LIS. (Seep. 79.) 



Maci'ocyclis concava, Say. 



Shell depressed, very slightly convex on the upper surface ; epider- 

 mis whitish horn-color, sometimes with a tinge of green ; whorls 5, 

 above flattened, below rounded, finely striate obliquely, rio. 209. 

 and sometimes with microscopic revolving lines, the outer 

 whorl spreading a little towards the aperture ; suture 

 rather deeply impressed ; umbilicus wide, deep, exhibit- 

 ing all the volutions to the apex; aperture rounded, 

 somewhat flattened above, its edge frequently tinged 

 with reddish brown ; jieristome subreflected at its colu- 

 mellar extremity, simple above, and in some specimens ^cfrocyciis concava. 

 considerably depriessed near its junction with the outer whorl j colu- 



