MR. J. W. KIRKBY ON PERMIAN FISH AND PLANTS. 75 



The lateral line is well marked by a series of deeply notched 

 and channeled scales in the dorsal half of the body. 



None of the specimens discovered show the slightest traces of 

 the endoskeleton. 



In one example we obtain some idea of the food of this fish ; 

 for intercalated between the scales of each flank, there may be 

 seen portions of a Palceoniscus varians, which undoubtedly repre- 

 sent the remains of an undigested individual that had been 

 captured and swallowed by the Acrolepis a short time previous 

 to its death. 



I at first identified this species with the Acrolepis Sedgivickii 

 of Agassiz ; but later comparisons of my specimens with Agassiz's 

 descriptions and figures have shown me that it differs from that 

 species in several particulars that appear of importance : for in- 

 stance, the anal fin of A. Sedgwickii is described as being much 

 greater than the dorsal, whereas, in the present species, the 

 difference between these fins is only slight ; the scales would 

 also appear much more regular in size and shape in A. Sedgivickii 

 than in the present species ; and the former fish would appear to 

 have been twice as large as the latter. I therefore cancel the 

 identification I formerly made. 



Prom A. asper, Ag., of the Kupferschiefer, the present species 

 differs more than from A. Sedgwickii. But there are four species 

 from the same formation, namely, A. angustus, Minister, A. in- 

 termedins, Minister, A. giganteus, Minister, and A. exsculptus, 

 Grermar, of which I have not been able to see either figures or 

 specimens, that may possibly approach more nearly than those I 

 have just noticed. For these reasons it only seems judicious to 

 refrain from attaching a specific name to the species, it being at 

 least possible that it may ultimately prove to belong to one of 

 these last-mentioned forms. 



The present species has occurred in the fish-bed, in the Grey 

 Stone overlying, and in the Dun Stone in the New Quarry at 

 Fulwell ; and I have taken a single example from the fish-bed in 

 the Old Quarry of the same place. 



