276 PUOCEEUINGS OF THE MALACOLOGICAL SOCIETY. 



the anterior part, quite the appearance of shag;reen ; it is also veiy 

 foliaceous, as though the outer concentric layers of the guard were 

 loosely superimposed. This is especially the case on the ventral 

 surface between the two longitudinal grooves and on the dorsal 

 surface. The internal structure of the guard is coarsely crystalline, 

 and does not at all distinctly show the concentric lamellae, such as are 

 so conspicuous in the Belemnite rostrum. The phragmocone extends 

 through about three-fourths of the length of the specimen ; its section 

 is almost circular ; its sides are inclined to each other at an angle of 

 13°, the angle between the dorsal and ventral surfaces being 12°. 

 The septa, as seen at a fracture at about the middle of the specimen, 

 are oblique, their lowest part being on the siphuncular side, i.e., 

 on the side adjacent to the two longitudinal grooves, and they have 

 only a very slight ventral lobe. 



The affinities of the fossil are quite clear. It is allied, on the one 

 hand, to the genus Bayanoteiithis from the Eocene of Ronca and of the 

 Paris Basin ; and, on the other hand, to the genus Vasseuria from the 

 Eocene of France. 



The genus Bayanoteuthis was instituted by Munier-Chalmas ' for 

 a species (which he did not name) from the "sables de Beauchamp " 

 (Upper Eocene) at Bremier, and for the species from the Eocene of 

 Konca that was described and figured by TJ. Schlonbach under the 

 name Belemnites rxigifer} Munier-Chalmas did not give a detailed 

 diagnosis of the genus, of which only a few fi'agments are known, but 

 merely stated that it differed from true Belemnites by the possession 

 of two sublateral grooves, and by the oval section of its naiTower 

 and more elongate phragmocone. But TJ. Schlonbach's figures and 

 descriptions of his species, B. riigifer, are quite sufficient to indicate 

 the characters of the genus. However, a diagnosis of the genus was 

 subsequently given by M. Paul Fischer^ and afterwards by Zittel.* 

 In this genus the guard is elongated, subcylinrlrical, tenninated 

 posteriorly in a point, and bearing two longitudinal, broad, shallow, 

 smooth, lateral grooves ; the dorsal surface is ornamented with 

 longitudinal coarse impressions ; the alveolus is unusually deep ; the 

 phragmocone is narrow, very slender, long, and in cross-section oval ; 

 the siphuncle is ventral ; and the septa, according to M. Fischer, 

 possess a feeble siphonal lobe. 



The present specimen differs from this genus in several important 

 characters : firstly, by the more conical form of the guard ; secondly, 

 by the presence of the deeply incised groove on each side of the 

 ventral surface ; and thirdly, by the more nearly dorsal position of the 

 broad shallow dorso-lateral grooves. 



The genus Vasseuria was instituted in 1880 by Munier-Chalmas,^ 



^ Bull. Soc. geol. France, ser. ii, vol. xxix (1872), p. 530. 



2 Jahrb. d. k.k. geol. Reichsanst., Wien, Bd. xviii (1868), pp. 455-461, pi. xi, 



figs. \a-h. 



3 "Manuel de Conchyliologie," fasc. iv (1882), p. 360. 



* " Haudbuch der Palpeontologie," Bd. i, Abtli. 2 (1884), p. 509. 



* Bull. Soc. geol. France, ser. iii, vol. viii (1880), p. 291. 



