Description of the Fossils in the older Deposits of the Rhenish Provinces. 36 1 



8. Pleurotomaria Beaumonti, nob., Tab. nost, XXXIII. f. 1, I a. 



Shell conical, composed of five volutions, of which the first are convex and the latter flattened. Volu- 

 tions ornamented with four or five equallj' separated, transverse striae, very finely granular toward 

 the summit of the spire. Upon the last volutions the granulations are changed into oblique, undu- 

 lated lamellar folds taking the direction of the lines of growth. Sutures canaliculated. The 

 angle which limits the base of the last volution is occupied by two small keels, between which 

 is seen the channel representing the fissure of the right lip, and marked with concave striEe. The 

 base of the shell has eight or nine radiating and undulating lines of growth. Aperture quadrangular, 

 subrhomboidal, with the lips disunited at the upper part. Left lip partly formed by the prolonga- 

 tion of the columella, which is thick and slightly arcuated. Right lip angular and furnished at 

 its internal angle with a rather deep fissure corresponding to the external channel. Height, 10 

 raillim. ; diameter of the ba-se, 1 1 . 

 This shell, upon which there still remain some traces of colour, consisting of brownish longitudinal 

 patches, is somewhat related to PL squamula (Phill. Geol. Yorks., Part 2, PI. XV. f. 17), and to the 

 Trochus Petraeos (Miinst. Beitrage, &c. iii. Heft, PL XV. f. 16); but the figures given by these authors 

 are too incomplete to establish a more precise approximation. 

 Villmar; rare. 



9. Pleurotomaria limhata, Phill. Geol. of Yorkshire, Part 2, PI. XV. f. 18. Var. Tab. nost., XXXIII. f.2. 



This shell, remarkable for its form, differs from that which Phillips has figured only in the fine, transverse 

 aad undulated striae which occupy the middle and lower part of the volutions, thus interrupting the 

 oblique folds, which are continuous in the variety from the mountain limestone. The slit of the right 

 lip would correspond to the line of union of the two superposed laminse which form the sharp and undu- 

 lated edge of the last volution. Traces of colouring may be observed upon the surface of this shell also. 



PafFrath; very rare. 



10. Pleurotomaria exaltata, nob., Tab. nost., XXXIII. f. 5. 



Shell conoidal, formed of eight angular volutions. A rounded and wide band or keel, neatly defined 

 by two striae, divides the volutions into two unequal parts, of which the upper is the larger and 

 concave, and the lower is convex. Upon the middle of the first the lines of growth which set off" 

 from the suture turn abruptly backward until they reach the keel ; upon the second, these striae, 

 setting off" from this same keel, first turn forward and then backward to take a radiating direction 

 toward the base of the shell. The arched striae of the keel are concave on the side of the aperture. 

 Suture deep and undulated by the folds which the striae of growth form. Base of the last volution 

 limited by a rounded varix. Lower surface of the shell flattened and covered with striae which 

 converge toward a probably very small umbilicus. Aperture transverse, subpentagonal. Left lip 

 unknown. Inferior edge almost horizontal and slightly arcuated. Right lip angular and furnished 

 with a wide and deep fissure which corresponds to the external band or keel. Height, 70 millim.; 

 diameter of the base, 75. 



This fine species, whose form approaches that of a Chinese pagoda, was found at Refrath by Dr. 

 Hasbach. 



1 1 . Pleurotomaria delphinuloides, Helicites delphinuloides, Schlot., Petref., PI. XI. f. 4. Tab. nost., XXXIII. 



f. 4. var. f. 4 a. 



We have given a new representation of this species which is very imperfectly figured in Schlotheim's 

 work. The shell is not even in perspective, and the drawing does not show the disposition of the stria 



