PLATE XX. 



Fig. Page. 



1. Aspidorhynchus fisheri, Egerton ; almost complete fish, right side view, 



nearly two-thirds nat. size, with remains of branchial arches (1 a) and 

 some dorsal caudal scales (1 b) enlarged three times. — Middle Purbeck 

 Beds ; Swanage. The type specimen. Dorset County Museum, 

 Dorchester, a., anal fin ; d., dorsal fin ; plv., pelvic fins. 97. 



2. Ditto ; head, etc., left side view and partly upper view, three-halves nat. 



size. — Ibid. British Museum, no. 28621. ag., angular; cl., clavicle; 

 d., dentary ; fr., frontal; hm., hyomandibular ; mx., maxilla; op., 

 operculum ; pa., parietal ; pas., parasphenoid ; pet., pectoral fin ; 

 pmx., p rem axilla ; ps., presymphysial bone; qu., quadrate; smx., 

 supramaxilla; si/., symplectic ; x., probably epiotics. 97. 



3. Ditto ; portion of abdominal squamation, nat. size, with (3 a) three ventral 



scales five-halves nat. size. — Ibid. Museum of Practical Geology, 

 London, no. 28440. 99. 



4. Ditto ; dorsal caudal scales, three times nat. size. — Ibid. Beckles Collec- 



tion (B. M. no. P. 6380). 99. 



5. Pholidophorus ornatus, Agassiz; imperfect tail, nat. size, with scale (5 a) 



enlarged twice. — Ibid. The type specimen. Mantell Collection 

 (B. M. no. P. 7583). a., anal fin; plv., pelvic fin; v., vertebral 

 centrum. 102. 



6. Ditto ; small fish, left side view, nat. size, with (6 a) jaws enlarged twice, 



and (6 b) abdominal flank-scales enlarged three times. — Ibid. 

 Alexander J. Hogg Collection (B. M. no. P. 10011). ag., angular; 

 </., dentary; mx., maxilla; pmx., premaxilla ; smx., supramaxilla. 102. 



7. Ditto ; caudal scales of lateral line, outer view, five-halves nat. size, and 



abdominal ventral scales (7 a) of same specimen, inner view, three 

 times nat. size. — Ibid. British Museum, no. 43038. 105. 



8. Ditto; abdominal ventral scales, outer view, three times nat. size. — Ibid. 



Museum of Practical Geology, London, no. 28439. 105. 



