356 Viscount d'ARCHiAc and M. de Verneuil's 



growth turn abruptly backward as they approach the middle keel, and then forward again after 

 having crossed it. Upon the base of the last volution tliey are arched and converge toward the ex- 

 tremity of the canal which terminates it. A granular cord parallel to the keel may be seen also at 

 the base of this last volution. Aperture elongated, rounded in the middle. Columellar lip covered 

 with a narrow callosity which extends from the upper angle to the base of the aperture. Canal 

 verj' short. Right lip furnished in the middle with a narrow and deep notch corresponding to the 

 keel. Height, 35 millim ; diameter of the last volution, 13. 

 We had at first referred to this species (Bull, de la Soc. Geol. de France, t. xii. p. 154) the Buccinum 

 spinosum, Min. Conch., Tab. DLXVI. f. 4, but Mr. J. Sowerby's figures 24-27 of plate LVII. of the 

 ' Memoir' of Sedgwick and Murchison (Geol. Trans., vol. v.), and those o{ Murch. spinosa (Phil. Pal. 

 Fos., PI. XXXIX. f. 192), have led us to consider the Devonshire shell as different from those which we 

 describe, as well in the form of the mouth as of the tubercle on the last whorl. We have named the 

 shell from the banks of the Rhine M. coronata, which appears to have been given by Goldfuss to one of 

 his varieties, and which we found quoted in the Memoir of Beyrich (Beitrage, &c., p. 15). 



Found in all the Strygocephalus limestones of the banks of the Rhine, Paifrath, Hagen, Iserlohn 

 Villmar, Sotenich, &c. ; very common. 



Var. a. Shell conoidal, very much shortened ; tubercles smaller, more numerous and less oblique. 

 From the same localities. 



2. Murchisonia intermedia, nob.. Tab. nost., XXXII. f. 4. Var. a, f. 5. 



Shell turriculated, pointed at the summit, composed of eight or nine convex volutions. Suture deep, 

 accompanied by a decurrent granular varix, less elevated than the keel. The latter is scarcely sa- 

 lient, but well marked by two parallel threads. Striae of growth disposed as in the preceding spe- 

 cies. Aperture oval, contracted at its extremities. Columellar lip covered with a callosity which 

 hides a very small umbilicus and rises again to the upper angle of the aperture. Columella rather 

 twisted, recurved in form of an S. Canal very short and not deep. Right lip thin, sharp-edged, 

 furnished with a narrow and deep notch which corresponds with the keel. Height, 35 millim. ; 

 diameter of the last volution, 13. 

 Var. a. f. 5. Tubercles slightly marked, often blended together and then forming a continuous varix. 

 Keel salient, more elevated than the varix. The granular ridge at the base of the last volution is scarcely 

 distinct. Shell more elongated than the preceding, and of which the volutions appear to be imbricated. 

 Height, 42 millim. ; diameter of the last volution, 15. * 



Var. b. Shell very short, conical and resembling a little Trochus. 

 Paffrath ; common, with the preceding. 



3. Murchisonia angulata, Phil. Pal. Fos., PI. XXXIX. fig. 189. Rostellaria, id. Geol. of Yorks., Part II., 



PI. XVI. fig. 16. Tab. nost., XXXII. f. 6. Var. a, f. 7. 



Shell conoidal, volutions increasing rapidly, very excavated. Varix not strongly marked. Keel ele- 

 vated, double, angular, channeled. Suture very deep. Lines of growth similar to those of the 

 preceding ; aperture rounded and not so high. Height, 42 millim. ; diameter of the last volution, 21. 



Var. a. f. 7. Shell more elongated than the typical variety. Varix none. Keel elevated, sharp-edged, 

 single to the summit, where nothing is perceived representing the channel of the other variety. A 

 second, less evident keel, on the base of the last volution. 



Paffrath ; with the preceding, common. Petherwin (Cornwall), Brushford (North Devon). Paffrath, 

 Vise (Belgium), in the mountain limestone. Bolland, ibid. 



4. Murchisonia bilineata, nob. {nan Phil. Pal. Fos.) Turritella bilineaUt, Goldf. Bonn Mus. Melania, 



id. ib., Tab. nost., XXXII. f. 8. 



