124 



BRITISH BELEMNITES. 



Young and Bird, in their volume on the Yorkshire coast (ed. 1, 1822), notice a 

 similar Belemnite, and give a figure (pi. xiv, fig. 4), and name it B. excentralis, describing 

 it as found in the " Oolite, Upper (Speeton) Shale, and Chalk." This is incorrect, but, as 

 will be seen, the large Speeton Belemnite belongs to the same natural group. 



De Blainville, in 1827, describes and figures in his pi. iii, fig. 8, 8«, B. excentricus, 

 froni Vaches-Noires, remarking that Miller's B. abbreviatus much resembles it. 



D'Orbigny revives Young and Bird's name for a species which he figures (pi. xvii) ; 

 but in the text (p. 120) he makes no reference to those authors, and uses the name 

 given by Blainville. 



In the second edition of the first volume of my work on the ' Geology of Yorkshire ' 

 I restored to the great Belemnite of the Malton Oohte the name assigned by Miller, and 

 mentioned the large Speeton Belemnite as B. lateralis. An undescribed form in the 

 Kimmeridge Clay of Oxfordshire, and another in the Tealby beds of Lincolnshire, will 

 complete this series of excentral Belcmnites, as far as I know them. 



Belemnites abbreviatus, Miller. Pis. XXXIV, XXXV, figs. 84 — 93. 



Reference. B. niyer maximus. Lister, 'Hist. Anim. Angliae,' p. 226, 1678. 



Belemnites maximus oxyrrhynclms, Lhvvyd. (No. 1667.) 1699. 



B. excentralis (in part), Young and Bird, ' Geology of the Yorkshire 



Coast,' pi. xiv, fig. 4, 1822. 

 B. abbreviatus, Miller, ' Geol. Trans./ 2nd series, vol. ii, pi. vii, 



figs. 9, 10, 1823. 



B. excentricus, Blainville, 'Mem. surles Belemn.,' p. 90, pi. iii, f. 8, 1827. 

 B. excentricus (also called excentralis), D'Orbigny, ' Pal. Frang., Terr. 

 Jur.,^ p. 120, pi. xvii, 1842. 



Guard. CyHndrical ; sides flattened or somewhat hollowed longitudinally ; apex 

 produced, compressed, sometimes incurved; ventral surface broader than the dorsal; a 

 flattening near the apex, on the ventral surface. 



Very old specimens have the apicial region much compressed, produced, and incurved ; 

 sides flattened by broad, shallow, longitudinal depressions, Avhich continue over a part of 

 the alveolar region, and are there gradually lost. 



Young specimens are shghtly hastate, very young ones distinctly so, with little trace 

 of the lateral hollow. 



Longitudinal sections show the axial line to be very excentric, especially so in the 

 retral part of the guard, and in old specimens considerably curved. 



Transverse sections present a somewhat four-sided outline, the ventral surface being 

 struck to a flatter curve than the dorsal, and the sides flat or a little concave. 



The length of a very large example is 8 inches ; of another smaller, but extending 



