﻿ICHTHY0D0RULITE3. 



155 



Genus EUCTENIUS, Traquair. 

 [Geol. Mag. [2] vol. viii. 1881, pp. 36, 334.] 



Small dermal defence somewhat elliptical in shape, laterally com- 

 pressed, convex on one side, concave on the other, with one margin 

 nearly straight, the opposite margin evenly convex, one extremity 

 rounded or bluntly pointed, and the other tapering to a point, or 

 produced into a long narrow extension. Convex margin divided 

 in a comb-like manner into a series of closely arranged, acutely 

 pointed denticles. 



Fossils of this character have been assigned by Anton Fritsch to 

 the cloacal region of certain Permian Amphibia under the name of 

 " Kammplatten." l 



Euctenius unilateralis (W. J. Barkas). 

 1869. Ctenoptychius, T. P. Barkas, Geol. Mag. vol. vi. p. 43, woodc. figs. 

 1, 2. 



1873. Ctenoptychius, T. P. Barkas, Coal Meas. Palaeont. p. 18, figs. 

 22, 23. 



1874. Ctenoptychius unilateralis, W. J. Barkas, Monthly Rev. Dental 

 Surgery, vol. ii. p. 484, figs, xvi, xvii. 



1875. Ctenoptychius unilateralis, J. Ward, [Proc] N. Staffs. Nat. Field 

 Club, p. 220. 



1881. " Ctenoptychius " unilateralis, R. H. Traquair, Geol. Mag. [2] 



vol. viii. p. 335. 

 1890. Euctenius unilateralis, J. Ward, Trans. N. Staffs. Inst. Mining 



Engineers, vol. x. p. 152, pi. ii. fig. 14. 



Type. Collection of T. P. Barkas, Esq., Newcastle-upon-Tyne. 

 The type species. 



Fig. 13. 



Euctenius unilateralis (Barkas). — Coal-Measures, Newcastle-upon-Tyne. 

 The upper figure is twice, and the lower figure thrice the natural size. 



Form. <$f Loc. Coal-Measures : Staffordshire, Northumberland, and 

 South Scotland. 



3 Fauna der Gaskohle, vol. i. (1880), pi. xx. See also R. H. Traquair, Geol. 

 Mag. [2] vol. viii. (1881), p. 334, and T. Stock, Ann. Mag. Nat. Hist, [5] vol. viii. 

 (1881), p. 90. 



