70 EXPLANATION OF PLATE 44". 



Fig. 13. Chambered alveolar cone and horny sheath of a 

 large Belemnite from the limestone of Solenhofen ; 

 the calcareous sheath or Belemnite itself has dis- 

 appeared. (Munster.) 



Fig. 14. Belemnites brevis? from the Lias at Lyme; 

 Nat. size. The length of the shaft of this Belem- 

 nite does not exceed that of the Beloptera (Fig. 15;) 

 a small fragment only of its alveolus is preserved, 

 but the place it occupied is filled with calcareous 

 spar, and the hollow cone above it with lias. (Ori- 

 ginal.) 



Fig. 15. Beloptera. In this fossil we have an intermediate 

 link between the Belemnite and the shell or sheath 

 of Sepia officinalis, a. represents the apex of the 

 sheath, e. e. its posterior expansion, analogous to 

 that at Fig. 4. e. e. and at Fig. 4'. e'j e' is its ante- 

 rior expansion, bearing on its internal surface an- 

 nular marks derived from the transverse septa of the 

 alveolus. (Blainville.) 



Plate 44". V. I. p. 282. Note. 



All the figures in this Plate are of nat. size. 



Fig. 1. Anterior sheath and Ink-bag of Belemno-sepia 

 discovered by Miss Anning in 1828 in the Lias of 

 Lyme Regis, and noticed by Dr. Buckland (Lond. 

 and Edin. Phil. Mag. May, 1829, P. 388,) as "de- 

 rived from some unknown Cephalopod, nearly allied 

 in its internal structure to the inhabitant of the 

 Belemnite." This sheath is, for the most part, na- 

 creous ; in some places (d. d.) it retains the condi- 

 tion of horn. The corrugations on its surface indi- 

 cate the lines of growth. Axf. a transverse fracture 

 shows the neck of the ink-bag. (Original.) 



Fig. 2. The lower part of Fig. 1. seen from another side; 



