﻿PLATYBOMATIDJE. 529 



anterior border ; principal flank-scales much deeper than broad, 

 with large peg-and-socket articulation ; dorsal and ventral scales 

 somewhat broader than deep, with well-defined inner keel, but no 

 peg-and-socket ; scales of upper caudal lobe acutely lozenge-shaped. 

 Well-developed ridge-scales present only upon the caudal pedicle 

 and upper caudal lobe. 



Eurynotus crenatus, Agassiz. 



1835. Eurynotus crenatus, L. Agassiz, Poiss. Foss. vol. ii. pt. i. p. 154, 



pis. xiv. a, b. 

 1835. Eurynotus Jlmbriatus, L. Agassiz, ibid. p. 157, pi. xiv. c. figs. 1-3. 



[Portions of trunk ; Oxford Museum.] 

 1835. Eurynotus crenatus, S. Hibbert, Trans. Eoy. Soc. Edinb. vol. 



xiii. pi. vii. fig. 4. 

 1844. Plectrolepis ruyosus, L. Agassiz, torn. cit. p. 306 (name only). 

 1850. Plectrolepis ruyosus, Sir P. Egerton, Quart. Journ. Geol. Soc. 



vol. vi. p. 4. [British Museum.] 

 1854. Platysomus declivus, J. Morris (ex Agassiz, MS.), Cat. Brit. Foss. 



ed. 2, p. 339 (name only). [Distorted fish ; British Museum.] 

 1867. Eurynotus jimbriatus, R. H. Traquair, Trans. Roy. Soc. Edinb. 



vol. xxiv. p. 710, pi. xiv. figs. 8, 9. 

 1879. Eurynotus crenatus, R. H. Traquair, ibid. vol. xxix. p. 349, pi, iij. 



figs. 1-16. 

 1881. Eurynotus crenatus, R. H. Traquair, ibid. vol. xxx. p. 54. 

 1890. Eurynotus ci'cnatus, R. H. Traquair, Proc. Roy. Soc. Edinb. 



vol. xvii. pp. 392, 400. 



Type. Imperfect fishes ; Edinburgh Museum (in part). 



The type species, attaining a length of about 0-25-0-3. Maxi- 

 mum depth of trunk equalling about one-third of the total length ; 

 the dorsal contour angulated at the origin of the dorsal fin, the 

 ventral contour gently arched. Head and opercular apparatus 

 small, occupying scarcely more than one-sixth of the total length ; 

 external bones ornamented with coarse striae, often concentric; 

 maxilla elongated, irregularly triangular, somewhat more than 

 twice as deep behind as in front, the majority of its superficial 

 striations vertical. Ein-rays and fulcra robust and smooth, the 

 rays of the dorsal sometimes serrated posteriorly ; pectoral fins 

 more than twice as large as the pelvic pair, as deep as the anterior 

 portion of the dorsal ; anal fin deeper than long, terminating oppo- 

 site the hinder extremity of the dorsal. Scales of moderate size, 

 those of the anterior portion ornamented with delicate oblique striae 

 terminating in the posterior serrations, the striae becoming obsolete 

 towards the caudal region. 



PART II. Z M 



