CARBONIFEROUS FOSSILS OF IRELAND. 33 



Naticopsis. if' Coy. 



Gen. C/i.— Shell globose; inner lip smooth, flattened, slightly thickened ; spire very small; umbilicus 

 none. 



In this genus arc included several fossils of the carboniferous limestone, provisionally placed by the late 

 Mr. Sowerby, Professor Phillips, and others, in the genera Ampullaria, Natica and Nerita. From Natica and 

 Ampxdlaria it is distinguished by the want of an umbilicus, and the flattened pillar ; from the latter genus it 

 also differs, in being a marine shell ; the smooth inner lip chstinguishcs it from Nerita. The operculmn 

 which I have seen two or three times. Is quite distinct from that o£ Natica or Nerita, as will be seen by a 

 glance at the figure, PI. III. fig. 9, which is from a specimen presented by Mr. Newenham, of Cork. 



Naticopsis canaliculata. M'Coy. (PL VII. fig. 3). 



Sp. C^.— Globose; body whorl large ; spire depressed of three inflated whorls; sutures deeply channeled ; 

 mouth slightly dilated ; shell very thin ; volutions delicately striated across. 



The thin shell, and channeled sutures of the spire, in this species, remind us strongly of Ampullaria. The 

 spire is rather larger than is usual in this genus, and though depressed, the whorls are remarkably convex ; the 

 deeply canaliculated suture distinguishes It from all others of the genus. 



Naticopsis dubia. M'Coy. (PL VIL figs. 2 and 2a). 



Sp. Ch. — Transversely ovate, very much depressed ; spire of three rather convex whorls ; mouth trans- 

 versely ovate ; surface smooth ; base convex. 



I have seen only one specimen of this curious species ; it is more depressed than any other of the o-enus • 

 length ten lines, width two and a quarter Inches. 



Naticopsis elongata. Phil. sp. 



Natica elongata. Phil. Geol. York. 



Sp. Ch. — Elongate, very obliquely oval ; spire prominent, mammillary, of two Imperfect volutions ; sur- 

 face with very delicate, oblique strise. 



This species Is remarkably elongate In form ; the spire is almost wholly exserted ; the surface is smooth, 

 with the exception of some very fine lines of growth. Length two inches, diameter one inch three 

 lines. 



Naticopsis neritoides. M'Coy. (PI. V. fig. 25). 



Sp. CT.— Globose, smooth; length one-fourth less than the width ; spire very small, flat, of two whorls; 

 aperture largo, semicircular ; outer lip thin ; Inner lip perfectly straight, thickened, convex. 



This Httle shell, by its general form, minute spire, stralghtness of the inner lip, and lar"e, semicircular 

 apertm-e, approaches the true Nerita, Linn., so closely, that we might include It In that genus, were It not 

 for the absence of any teeth on the pillar, whicli, besides, is slightly convex and thickened, as In Naticopsis, 

 M'Coy ; it is, therefore, better to include It in the fossil genus I have already estabhshed for shells having this 

 peculiar character of columella, while the specific name will indicate the analogy I have pointed out. Length 

 two and a half lines, width three lines. 



Naticopsis Phillipsii. il/' Coy. (PI. III. fig. 9, and PL VL figs. 4a and Ab). 



Natica elliptica? Phil. Geol. York. 

 Sp. Ch. — Body whorl large, obliquely oval ; spire very small, depressed, of four convex turns; surface 

 perfectly smooth, except at the sutures, which are elegantly marked with sharp, short stria ; inner lip very much 

 thickened ; convex above, flattened or concave below. 



