﻿PLATYSOMATIDJE. 533 



Mesolepis scalaris, Young. 



186G. Mesolepis scalaris, J. Young-, Quart. Journ. Geol. Soc. vol. xxii. 



p. 313. 

 1875. Mesolepis scalaris, J. Ward, [Proc] N. Staffs. Nat. Field Club, 



p. 235. 

 1879. Mesolepis scalaris, R. 11. Traquair, Trans. Roy. Soc. Edinb. 



vol. xxix. p. 355, pi. iv. figs. 1-5. 

 1890. Mesolepis scalaris, J. Ward, Trans. N. Staffs. Inst. Mining Engin. 



vol. x. p. 182, pi. vii. figs. 10-14. 



Type. Pish; collection of John Ward, Esq., Longton. 



Dorsal contour of trunk strongly arched, the maximum depth, at 

 the origin of the dorsal fin, nearly equal to the length of the trunk 

 from the pectoral arch to the base of the caudal fin. ; caudal pedicle 

 short and narrow. Head and opercular apparatus occupying about 

 one-third of the length to the base of the caudal fin ; teeth of lower 

 jaw tumid distally. Pelvic fins arising midway between the pec- 

 torals and the anal ; dorsal fin very high in front, its maximum 

 height contained two and a half times in the depth of the trunk at 

 its origin ; caudal fin very large and deeply cleft. Tuberculations 

 of scale-ornament confluent into short, fine, vermiculating ridges. 



Form. Sf Loc. Coal-Measures : North Staffordshire. 



Not represented in the Collection. 



The following specimen is of undetermined species. In some 

 respects it is suggestive of M. rJiomba ; but although very coarsely 

 rugose, the scales are at least as broad and large as in the type 

 species. 



P. 4084. Fragmentary remains of the head and trunk, about 0*105 

 in length, exhibiting regular coarse striations on the 

 opercular bones, and an irregular rugosity of angularly 

 bent ridges on the scales ; Calciferous Sandstone, Eskdale. 



Purchased, 1883. 



The following species have also been briefly described, but do not 

 appear to be represented in the Collection : — 



Mesolepis microptera, R. H. Traquair, Trans. Roy. Soc. Edinb. 

 vol. xxix. (1879), p. 356, pi. iv. fig. 8.— Lower Coal- 

 Measures (Dalemoor Rake Ironstone) ; Stanton-by-Dale, 

 Derbyshire. [Imperfect fish ; E. W. Binney Collection.] 



Mesolepis rhomba, R. H. Traquair, Ann. Mag. Nat. Hist. [6] 

 vol. vi. (1890) p. 493. — Calciferous Sandstones (Cement- 

 stone Group) ; Eskdale, Dumfriesshire. [Imperfect fish ; 

 Edinburgh Museum.] 



Mesolepis tubercidata, R. H. Traquair, ibid. p. 493. — Ibid. 

 [Ditto.] 



