﻿384 CROSSOPTEUYGTT. 



Type. Scales and head-bones ; collection of James Thomson, Esq., 

 Glasgow. 



Proportions of bones and scales, so far as known, resembling 

 those of the type species. Ganoine covered with numerous small, 

 closely-arranged, blunt tuberculations. 



Form. SfLoc, Coal-Measures : Lanarkshire, Northumberland, and 

 Staffordshire. 



P. 4590. Left mandibular ramus, 0*135 in length, but imperfect 

 anteriorly and exhibiting only the bases of the teeth : 

 also an associated dermal plate and scale ; Low Main 

 Seam, Newsham, near Newcastle-upon-Tyne. 



Enniskillen Coll, 



P. 5494, P. 5137. Hinder portion of a similar mandibular ramus 

 and a fragment ; Newsham. Of the first specimen, a 

 portion of the ornament is shown, five times the natural 

 size, in PI. XIII. fig. 5. 



Presented by William Dinning, Esq., 1888. 



Megalichthys intermedius, sp. nov. 



1866. Rhomboptychius, J. Young (ex Huxley, MS.), Quart. Journ. Geol. 



Soc. vol. xxii. pp. 597, 604, woodc. figs. 1, 2. [Imperfect fish ; 



Andersonian Museum, Glasgow.] 

 (?) 1870. Megalichthys rugosus, J. Young, Rep. Brit. Assoc. 1869, 



Trans. Sect. p. 102. [Specifically indeterminable decorticated 



bones; collection of James Thomson, Esq., Glasgow.] 

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



p. 230, fig. 6. 

 (?) 1875. Megalichthys rugosus, J. Ward, ibid. p. 229. 

 1890. Megalichthys rugosus, Woodward & Sherborn, Cat. Brit. Foss. 



Vertebrata, p. 118. 

 1890. Rhomboptychius, J. Ward, Trans. N. Staffs. Inst. Mining Engin. 



vol. x. p. 166, pi. ii. figs. 6, 24, pi. viii. fig. 9. 



Type. Portions of head ; British Museum. 



A species attaining a somewhat larger size than the type. Man- 

 dible elongated, not less than five times as long as deep ; posterior 

 expansion of maxilla relatively deep ; larger teeth smooth or finely 

 striated, often transversely banded, and sometimes with one or two 

 rings of slight, vertically elongated indentations. Each of the pair 

 of jugular plates about two and a half times as long as broad, 

 rounded or obliquely truncated posteriorly. Ring-vertebrae much 

 more slender than in M. hibberti ; superficial ganoine upon the 



