O FISH OF THE CARBONIFEROUS PERIOD. 



structure resembles that of Psammosteus generally, that is, four 

 or five dense horizontal layers at the surface, beneath which the 

 substance is composed of large irregular cells, about half their 

 diameter apart, but irregularly arranged in the blastema. 



From the yellow sandstone shale of Fallaghloon, Maghera, 

 Ireland. 



{Col Mr. Griffith at DubHn.) 



Chelyophorus Griffithii (M'Coy). 



The specimens to which I give this name consist of a small jaw- 

 bone, resembling the glossohyal in shape, about 11^ lines long, 

 obtusely pointed at the anterior end, and gradually increasing to 

 nearly 2 lines in depth towards the posterior extremity, which is 

 abruptly acuminated or wedge-shaped; the upper edge shows seven 

 or eight small, curved, smooth conical teeth, their length rather 

 more than twice their width, and the distance between them 

 rather greater than their length ; the surface of the margin has 

 three or four rows of slightly elongate, closely-placed tubercles ; 

 towards the middle and lower part of the bone the tubercles elon- 

 gate into short ridges, arranged in lines, which meet at an angle 

 of 45° along the middle of the side, the angle pointing back- 

 wards on the posterior half, and forwards on the anterior half, 

 so as to have a confused rhombic space at the middle of the bone ; 

 all the ridges and tubercles are glossy, very closely placed, and 

 finely crenulated at their margins. The second specimen is a 

 bone probably from the side of the occiput, resembling the por- 

 tions of Chehjophorus Verneuili (Ag.) in figs. 17 and 18. pi. 31a 

 of Agassiz, Monog. Old Red, "fee. ; the granulation of the scul- 

 ptured portion is rather more distinct, forming lengthened tu- 

 bercles in one part and subparallel ridges in another, and all mi- 

 nutely crenulated on the sides. The sculpturing of the two spe- 

 cimens is identical in character, both with each other and with 

 the old red Chelyophori, difiering from the C Verneuili princi- 

 pally in the crenulation of the side of the tubercles. 



They are both from the lowest carboniferous shales of Cultra, 

 Hollywood, county Down, Ireland. 



{Col Mr. Griffith at Dublin.) 



Coccosteus? carbonarius (M'Coy). 



Sp. Char. Mesial (ventral?) plate very narrow; sides converging at 

 an acute angle, apex rounded ; mesial keel obtusely rounded, 

 height in the middle one-fourth of the width ; surface closely 

 covered with rounded polished tubercles, varying from one- 

 fourth to one-half of a line in diameter (generally the latter), 

 each surrounded at its base by a little, closely applied, milled. 



