Description of the Fossils in the older Deposits of the Rhenish Provinces. 355 



ters constant enough to separate them. In fact, the B. Schlotheimii is always more elongated than the 

 B. arculatum, particularly the latter volutions, and it is contracted at the base. The simple suture is not 

 accompanied by an area nor a varix. The less conoidal shell, which is mucronated and often inflated 

 toward its middle part, resembles certain Mitres. The aperture also differs from that of B. arculatum. 

 The system ol" folds upon the first volutions, and lines of growth on the last, are, on the contrary, perfectly 

 similar in the two species. 



We refer the Buccinites subcostatus of Schlotheim to the B. Schlotheimii : it is an inflated variety of 

 it, as is also the Phasianella ventricosa of the Museum of Bonn. We have not preserved to it the name 

 of subcostatus, because that would seem to point out as a distinguishing character the only one that is pre- 

 cisely common to both species. We refer to this species, also, as a variety, an elongated and more regu- 

 larly conoidal shell, of which the upper part of the volutions, vrhich is concave, is covered with transverse 

 striae, which in crossing over very fine longitudinal folds form an elegant net-work upon that part of the 

 spire. 



Bronn unites to these two species the B. breve and B. imbricatum, Min. Conch., Tab. DLXVI. f. 3, 2, 

 but it is undoubtedly of the B. acutum (Ibid. f. 1.) that he intended to speak, as the B. breve has not the 

 least relation to B. arculatum. There are, however, so many species whose forms are nearly similar, that 

 it is difficult to make even tolerably certain approximations from mere figures. Thus the B. imbricatum 

 would be referable to the variety ticketed with the name of Phasianella ventricosa in the Museum of 

 Bonn. The figures 9, 17, 18, 19, and 20 of plate XVI. of Phillips (Geol. of Yorks., Part II.) might also 

 be referred to B. Schlotheimii, but the last volution is proportionally much higher than in any of our 

 varieties ; and the same with the aperture. As to the B. acutum of Mineral Conchology, it is certainly 

 very near to our species, but the figure given byPhillips seems to represent altogether a distinct shell. 



Faffrath ; very common. 



3. Buccinum breve (variety), Sow. Min. Conch., PI. DLXVI. f. 3. 



We regard as a mere variety of B. breve a shell which differs only in its spire, in which there are two 

 more volutions, and in the elongation of its last volution which renders the shell less globular and longer 

 than that of the Mineral Conchology. The absence of a notch at the lower edge of the aperture, inclines 

 us also to Mr. Sowerby's opinion, that this shell would be better placed with the Turbines. 



Paffrath ; rare. Limestones of Devonshire. 



MURCHISONIA. 



Generic character. Shell turriculated, aperture oblong, oblique, terminated at its base by a very short 

 canal. Columella arculated and slightly recurved outwards. A narrow, more or less deep fissure 

 on the right lip, with parallel edges, the successive filling up of which produces a single or double keel 

 upon the middle of the volutions, or a narrow continuous band, exactly circumscribed throughout 

 the whole height of the spiref. 



1. Murchisonia coronata, nob. Turritella spinosa, Goldf. Bonn Mus. Cerithium antiquum. Stein., 

 Mem. de la Soc. Ggol, de France, t. i. p. 367. Tab. nost., XXXIL f. 3. 



Shell turriculated, pointed at the summit, with ten or twelve convex volutions. Suture deep, edged 

 beneath with very salient, rather oblique tubercles, ten to each volution, and which are more ele- 

 vated than the middle keel. The latter is edged by two threads or narrow ridges. The striae of 



f For the details relative to the establishment of this genus and its species, see Bulletin de la Soc. 

 Geol. de France, t. xii. p. 154. ISil. 



