726 Davis — On the Fossil Fish-Remains of the Coal Measures of the British Islands. 



Diplodus gibbosus, 

 Diplodus gibbosus, 

 Diplodus tenuis, 

 Diplodus tenuis, 



Diplodus tenuis, 



Barkas, T. p., 1873, "Coal Meas. Palfeont.," 



p. 16, pi. I., figs. 6, 7, 9-13. 

 Barkas, W. J., 1874, "Monthly Rev. Dental 



Surgery," vol. ii., p. 346, figs. 1-4. 

 Woodward, A. S., 1889, " Cat. Foss. Fishes Brit. 



Mus.," pt. I., p. 11, pi. VI., figs. 2-4. 

 Ward, J., 1889, " Trans. N. Staffs. Inst. Mining 



and Mech. Engiu.," vol. x,, p. 140, pi. ii., 



fig. 1. 

 Woodward & Sherborn, 1890, " Cat. Brit. Foss. 



Verteb.," p. 67. 



III. — GiLLRAKERS. 



Stemmatodus, 

 Stemmatodus, 

 Stemmatodus, 



Stemmatodus, 



Stemmatodus, St. John & Wortlien. 



. St. John & Worthen, 1875, " Palseont. Illinois.," 

 vol. vi., p. 328. 



. Woodward, A. S., 1889, "Cat. Foss. Fishes," 

 vol. i., p. 245. 



. Ward, John, 1890, " Trans. N. Staff. Inst. Min- 

 ing and Mech. Engineers," vol. x., p. 153, 

 pi. II., fig. 22. 



. Woodward & Sherborn, 1890, " Brit. Foss. 

 Verteb.," p. 188. 



The teeth of Pleuracanthis Icevissimus, Ag., vary greatly in form; there are 

 two principal cones, circular, or more or less comj^ressed, with or without lateral 

 cutting edges, sometimes striated. The cones are divergent, and frequently 

 exhibit a slightly sygmoidal curvature. Between the two outer denticles is a 

 smaller intermediate one, which may be short and compressed or comparatively 

 long and slender. On the posterior surface behind the smaller intermediate 

 denticles is a "button," which forms tlie seat on which the anterior part of the 

 base of the succeeding tooth rested. The "button" is of irregular size, some- 

 times prominent, at others scarcely discernible, which is probably due to the 

 different relative positions occupied by the teeth. Base broad, extending 

 backwards, inferior surface more or less flattened. 



The spines of Pleuracanthus Icevissimus are straight, broad at the base, and 

 tapering upwards to a more or less pointed apex ; compressed antero-posteriorly, 



