50 EXPLAN ATION OF PLATE 29. 



Fig. 7. Upper surface of Fossil Loligo from the Lias of 

 Lyme Regis. A, A, Barbs of the Pen. B,B,Mar- 

 ginal bands. C, Axis of the Pen. d, upper plate 

 of marginal band, having an unusually corrugated 

 surface, which may be the result of imperfect growth 

 of the transverse fibres ; if fully expanded they would 

 probably have resembled those of the subjacent 

 Plate at d". (Original.) 



d'. Magnified representation of the rugous surface of d. 



d'". Magnified representation of the second plate of the 

 marginal band, Fig. 7. d". 



e. Upper surface of second Plate of the shaft of the pen ; 

 here the transverse wavy lines predominate over the 

 vertical straight lines ; but both are visible. 



f. Upper surface of third plate ; here the vertical straight 

 fibres prevail over the transverse wavy fibres. 



Plate 29. V. I. pp. 232 and 234. 



Fig, 1. Fossil Loligo from Lias at Lyme, in the col- 

 lection of Miss Philpot, exhibiting nearly the same 

 structure at figs. 6. 7. at PI. 28. and containing be- 

 neath the pen, a very large Ink bag, D. The greater 

 proportionate size of this Ink bag indicates a differ- 

 ence in species from fig. 3. (Mrs. Buckland. Ori- 

 ginal.) 



Fig. 2. Loligo Aalensis from Lyme Regis showing the 

 under surface or concave side, and the duct of the 

 Ink bag distended with Ink. A.A. Barbs or fila- 

 ments of the Pen; B.B. Marginal bands; C. Axis of 

 Shaft; D. Duct of Ink bag. (Mrs. Buckland. Ori- 

 ginal.) 



The wavy lines here seen between the Ink bag 

 and the apex of the Pen, are the inferior termi- 

 nations of the successive lamina? of growth ; each 



