﻿ctbxodontidje. 251 



elliptical in form, with numerous strong, outwardly directed ridges, 

 tuberculated or crenulated. Dorsal and anal tins continuous with 

 the caudal. 



The remains of this genus and of the closely allied Sa- 

 genodus (p. 2oo) are usually very fragmentary, and the paired 

 fins still remain unknown. The so-called Campylopleuron shows 

 the form of the tail ; but the only tolerably complete individuals 

 hitherto discovered ' are too imperfectly preserved for satisfactory 

 discussion. A general review of the principal skeletal features 

 already discovered is given by W. J. Barkas 2 , Miall ', and 

 Fritsch \ Cranial roof-bones are also discussed and figured 

 by Hancock and Atthey 5 and T. P. Barkas 6 ; the palate is 

 described by Miall 7 , Hancock and Atthey 8 , and T. P. Barkas 9 ; 

 the mandible by Atthey 10 ; and the teeth especially by Hancock 

 and Atthey " and W. J. Barkas VJ . The scales are first described and 

 figured by Hancock and Atthey 13 . 



Ctenodus cristatus, Agassiz. 



[Plate IY. fig. 1.] 



1826. " Palate," J. De C. Sowerby, Zool. Journ. vol. ii. p. 23, pi. ii. fig. 2. 

 1838. Ctenodus cristatus, L. Agassiz, Poiss. Foss. vol. hi. p. 137, pi. xix. 



fig. 16. 

 1868. Ctenodus cristatus, T. Atthey, Ann. Mag. Nat. Hist. [4] vol. i. 



p. 83. 

 18G8. Ctenodus tubercidatus, T. Atthey, ibid. p. 83. [Lower dental 



plates ; Newcastle-on-Tyne Museum.] 



1 Hancock & Atthey, Nat. Hist. Trans. Northurnb. & Durham, vol. iii. p. 55 ; 

 A. Fritsch, Fauna der Gaskohle, &c, Bohmens, toI. ii. p. 93, pi. lxxx. b. 



2 Proc. Roy. Soc. N. S. Wales, vol. x. (1877), pp. 99-123, and ibid. vol. xi. 

 (1878), pp. 51-64. 



3 L. 0. Miall, " On some Bones of Ctenodus" Proc. Yorksh. Geol. & Polyt. 

 Soc. n. s. vol. vii. 1880, pp. 289-299, with figs. 



4 A. Fritsch, Fauna der Gaskohle, &c, Bohmens, vol. ii. pt. 3 (1888). 



5 Nat. Hist. Trans. Northurnb. & Durham, vol. iv. p. 401. 



6 Coal Meas. Palseont. 1873, p. 113, figs. 244-246. 



7 Quart. Journ. Geol. Soc. vol.xxx. (1874), p. 772, pi. xlvii. 



8 Nat. Hist. Trans. Northurnb. & Durham, vol. iv. p. 399, pi. xiv. 



9 Coal Meas. Palseont. p. 114, fig. 247. 



10 Nat. Hist. Trans. Northurnb. & Durham, vol. v. p. 227, pi. v. figs. 1, 2. 



11 Ibid. vol. iii. p. 61 (dental plate). 



* 2 Proc. Roy. Soc. N. S. Wales, vol. x. (1877), pp. 99-109, with figs, 

 (palatine dental plates) ; ibid. p. 115 (vomerine teeth). See also T. Atthey, 

 Nat. Hist. Trans. Northurnb. & Durham, vol. v. (1875), p. 228, pi. v. fig. 4 

 (vomerine teeth). 



13 Nat. Hist. Trans. Northurnb. & Durham, vol. iii. p. 55 ; and loc. cit. vol. iv. 

 p. 398, pi. xiii. fig. 3, p. 417, pi. xvi. 



