BELEMNITES OF THE OXFORD CLAY. 



121 



3. Belemnites Owenii (tornatilis). pi. XXXII, fig. 80. 



The guard is very smooth, less compressed than in the typical forms ; more cylin- 

 drical, with a longer, deeper, and narrower ventral furrow (fig. 80). This furrow, indeed, 

 occupies the greater part of the axial length of the guard ; in middle-aged specimens an 

 old specimen shows some trace of lateral flattenings. From the Kelloway Rock of 

 Hackness and Scarborough. It is not unlikely that this may be found to deserve to be 

 regarded as distinct specifically. 



Belemnites strigosus, n. s. PI. XXXII, fig. 81. 



Guard. Very long, slender, cylindro-conical, compressed, acuminated, smooth, with 

 a distinct longitudinal furrow drawn from near the apex, on the ventral face, through 

 two fifths of the length of the axis, and thence continued in a slighter depression 

 towards the alveolar region. 



Transverse sections of the guard show an oval contour, the sides flattened ; the 

 venti-al face broader than the dorsal ; in the alveolar region the dorsal part of the shell is 

 much thicker than the ventral part. 



Greatest length of the one specimen seen 7^ inches, of which the axis is 62 inches ; 

 greatest diameter of an inch, 



Proport'mis. The diameter at the alveolar a])ex from back to front of an inch) 

 being taken at 100, that from side to side is about 80, ventral radius about 40, dorsal 

 radius about 60, axis ICOO. 



Phragmocone. Unknown. The alveolar section is nearly circular, the angle appears 

 to be about 20°. 



Locality. In the upper ])art of the Oxford Clay, in Cowley Field, near Oxford ; one 

 specimen, presented to the University Museum by W. B. Dawkins, M.A., the first 

 Burdett-Coutts Scholar. 



Ohsermiions. This remarkable fossil carries to extreme length the essential characters 

 of the group of tornatile Belemnites, the cylindro-conical outlines, the slight compression, 

 the apicial groove, and low angle of phragmocone. Having but one example to con- 

 sider, I am unable to describe the variations due to age and accident, but it would be 

 very agreeable to be furnished with evidence on these points. I have seen no foreign 

 specimens corresponding with this species; but D'Orbigny's fig. 3, pi. xvi, somewhat 

 resembles it. A thin white external layer appears on the specimen, not the fibrous layer 

 noticed in B. sulcatus and B. Owenii. 



