On the Fossil Fishes of the Carbonijerous Limestone Series of Great Britain. 443 
diminishing gradually forwards and ending in an obtuse point. The crown is 
convex, anteriorly convoluted, a central ridge extends from front to back of the 
tooth from which the surface slopes on each side, terminating in a slightly raised 
lateral margin. There are about eight transverse, wide, large, and rounded folds 
or wrinkles. The whole surface is enamelled and punctured. Posterior margin 
convex, depressed. Lateral margins straight or slightly convex, anterior ones 
incurved, pointed. 
An example in the Enniskillen collection shows the tooth, P. transversus, Ag., 
in juxtaposition with the anterior lateral margin of the tooth of P. jonesi, Ag. 
It occupies an exactly corresponding position to the second tooth of Deltodus, and 
in some respects bears a resemblance to that tooth. 
A comparison of the above description and the figures (PI. LIIL., figs. 20-23), 
with those given by Portlock in the Geological Report referred to, show that the 
two specimens figured by Portlock are both included in the species P. jonesii as 
originally named by Agassiz, and that Agassiz’s species P. transversus was not known 
to Portlock, his definition of the difference between the two being, that in the 
latter “the folds are continued more across the tooth, are less twisted, and not so 
strong.” The description given by Prof. M‘Coy of Pacilodus jonesit (+ P. trans- 
versus) is evidently founded on that of Portlock ; the specimens are not figured, 
_ but a reference to those in the Geological Report is given; there is no allusion to 
the median teeth, smaller, narrow, and more triangular in form, which Prof. 
Agassiz named P. transversus, and M‘Coy appears also to have accepted the 
slightly raised forms of the original P. jones as the P. transversus, Ag. An 
examination of the type specimens named by Prof, Agassiz in the Enniskillen 
collection proves both authors to have been in error. 
Formation and locality : Carboniferous Limestone, Armagh. 
Bex coll. Ear] of Enniskillen. 
Peecilodus obliquus, Agass., MSS. 
(Pl. LIIL., fig. 24.) 
Peecilodus obliquus—L. Agassiz, 1838. “Rech. sur les Poiss. Foss.,” Vol. IIT., p.174, indet. 
» » J. E. Portlock, 1843. “Rept. on Geol. Londonderry,” p. 461. 
” » C. G. Giebel, 1848. “Fauna der Vorwelt,” Vol. L., pt. 3, p. 337. 
) » H. G. Bronn, 1848. “Nomencl. Palont.,” p. 1022. 
” » H. G. Bronn, 1849. “Enumerator Paleont.,” p. 647. 
» 6 J. Morris, 1854. “Cat. Brit. Foss.,” p. 340. 
” » J. F. Pictet, 1854. “'Traité de Paléont., Vol. IL, p. 270. 
» » F. MCoy, 1855. “Brit. Palzoz. Foss.,” p. 640, pl. 3 L, fig. 5. 
) » Morris and Roberts, 1862. “Quart. Journ. Geol. Soc.,” Vol. XVIII, p. 101. 
” 9 Young and Armstrong, 1871. “Trans. Geol. Soc. Glasgow,” Vol. ILL, supt. p. 75. 
” » Armstrong, Young,and 
Robertson, ; 1876. ‘Cat. West Scot. Fossils,” p. 62. 
» J. J. Bigsby, 1878. “Thesaurus. Devonico-Carb.,” p. 363. 
