E. D. Wellbuni—Fish Fauna of Millstone Grit. 219 



Insertse sedis. 



I here place certain small Helodont teeth, one of which shows 

 the characters of H. triangularis, Davis, the latter, from its 

 unsymmetrical form, being in all probability a medio-lateral, and 

 others, which are smaller and more symmetrical, being symphyseal 

 teeth of Psephodus or some other Cochliodont fish. 



Form, and loc. : D Shales, Middle Grits, Summit. 



Family ACANTHODID^. 



Geuus ACANTHODES, Agassiz, 1833. 



Acanthodes Wardi, Egerton, 1866. 



The best specimen of this fish I found at Summit ; it shows the 



fish from a point a short distance in front of the pectoral fin spine, 



the basal portions of which are preserved, to a point some little 



distance behind the dorsal fin spine, which is also present. The 



body is clothed with small quadrate scales, which I am unable to 



distinguish from those of A. Wardi, Egert., of the Coal-measures. 



Besides the above, fragments of the fish and many fin spines have 



been found. 



Form, and loc. : D Shales, Middle Grits, Summit ; Boulder Clougb, 

 Sowerby ; and Kilne House Wood, Luddenden, near Halifax. 



Acanthodes, sp. nov. 



One fragment of Acanthodes shows characters which appear to 

 entitle it to specific distinction, viz., the scales are very minute and 

 are ornamented with fine diagonal striae. The only species of 

 Acanthodes that I know of with this scale sculpture is A. concinnus, 

 Whiteaves,^ but in this species the fin spines are ornamented with 

 " about four longitudinal grooves," whereas the present species shows 

 no evidence of these grooves, the fin spines being broad and elongated, 

 having a single groove and ridge running parallel with the anterior 

 border. On account of the scale sculpture I propose the specific 

 designation striatus for this species. 



Form, and loc. : D Shales, Middle Grits, Summit. 

 Genus CLIMATIUS, Agassiz, 1845. 

 Climatius, sp. ? 



Among the fish remains there is the crushed body of a small 

 Acanthodian fish of about 50 mm. in length. The body, which 

 appears to have been of a somev/hat slender form, is covered with 

 smooth quadrate scales, and there are several fin spines present, 

 some being detached from the body but lying in close proximity to 

 it ; the majority of the spines are broad and robust, the others being 

 straight, narrower, and more elongated, and all are ornamented 

 with coarse longitudinal ridges, and in general characters agree very 

 closely with those of the Old Ked Sandstone fish Climatius as 

 figured and described by Sir P. Egerton - and Mr. J. Powrie, F.G.S.' 

 I have also carefully examined the specimens of Climatius in the 



1 Trans. Roy. Soc. Canada, vol. vi, sect. 4. 



^ Mem. Geol. Survey, Fig. and descrip. organic remains, dec. x. 



^ Trans. Edin. Geol." Soc, vol. i. 



