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MISS JANE DONALD ON CAKBONIFEEOTJS 



the band there is a spiral thread about two thirds below the suture, 

 and immediately below the suture there is another fine thread on 

 the body-whorl, but it is not preserved on the other whorls. 



There is only one specimen of this shell in the Gilbertson 

 Collection in the Natural History Museum (no. G. 234). The 

 length of the four and a half whorls is 20 millim., width 12 millim. 



The shell has a slight resemblance to M. Archiaeiana, de Kon., but 

 the whorls are not so convex, the band is narrower and more 

 prominent, and the spiral lines below the band are beaded and 

 more numerous. Perhaps the general form most nearly approaches 

 that of M. spirata, Goldf., the type of which I have seen at Bonn ; 

 but the band of this species is formed of two keels, separated by a 

 small groove, and there are only two spiral lines below it, instead of 

 the numerous lines of M. pyramidata. 



Locality. Bolland. 



Formation. Carboniferous Limestone. 



Mtjkchisonia zonata, sp. nov. (Woodcuts, figs. 1, 2.) 



Shell conical ; whorls convex, separated by deep sutures. There 

 are only two specimens of this shell, and neither of them is entire, 

 but three whorls being preserved of each, and one specimen is a 



Fig. 1. — Murchisonia zonata, Fig. 2. — Cast of Murchisonia 

 Donald. Nat. size. zonata, Donald. 



From the Mountain Limestone of Narrowdale. 



mere cast. The sinual band is situated about the middle of each 

 whorl ; it is broad and flat, and is not raised above the surface of 

 the whorl ; it is bounded by two grooves. Below the sinual band 

 there are two narrower and slightly convex bands, separated by 

 grooves, and on the body-whorl there are two or three additional 

 bands and grooves. On the upper part of the whorl there are two 

 very shallow grooves, one of which is about midway between the 

 suture and the sinual band, and the other is just below the suture. 

 The lines of growth are only preserved on the upper part of the 

 body-whorl, where they are distinct and curve backwards to the 

 sinual band. The mouth is imbedded in the matrix. 



