EXPLAXATIOX OF PLATE 15. 27 



Oxford Museum, from the Lias at Lyme Regis, containing 

 within the ribs, a coprolitic mass of digested bones, inter- 

 spersed with scales of fishes, a, Furcula. b, Clavicle, c, 

 Coracoid bone, d, Scapula, e, Humerus. (Fisher. Ori- 

 ginal.) 



Plate 15. V. I. p. 147.) 



The specimens are all of the natural size except where 

 the figures denote otherwise. (Original.) 



1 and 2. Intestines of the two most common English 



species of Dog-Fishes, injected with Roman cement. 



The vascular structure, which is still apparent in 



the desiccated membrane, resembles the impressions 



on the surface of many Coprolites. 



3. Coprolite from the Lias at Lyme, exhibiting the spiral 

 folding of the plate of digested bone, and impressions 

 of the intestinal vessels and folds upon its surface. 

 (See Note, V. I. p. 152. et seq.) 



3'. Magnified scale of Pholidophorus limbatus, embedded 

 in the surface of the Coprolite, Fig. 3. This scale 

 is one of those that compose the lateral line, by which 

 a tube passes to convey mucus, from the head, along 

 the body of fishes ; a. is the hook, on the superior 

 margin, which is received by a depression on the 

 inferior margin of the scale above it, corresponding 

 with b. ; c. is the serrated edge of the posterior 

 margin, perforated at e. for the passage of the mu- 

 cous duct; d. is a tube on the interior surface of the 

 scale to carry and protect the mucous duct. (See 

 note V. I. p. 150.) 



3". Exterior of the scale 3'.; the same parts are repre- 

 sented by the same letters ; the larger portion is 

 covered with enamel ; the smaller portion next d. is 

 the bony root forming the anterior margin of the 

 scale. 



