434: PETEIFACTIONS AND THEIR TEACHINGS. CHAP. V. 



tion of the vertebral column between the principal lobes of 

 the tail, and the articulation of the caudal rays by inter- 

 apophyses. The fishes of this family are abundant in the 

 Carboniferous and Devonian formations, and there are a few 

 genera in the Triassic, Oolitic, and Cretaceous deposits : but no 

 ichthyolites of this family have been observed in strata above 

 the chalk. There are many splendid specimens of the prin- 

 cipal types in Case B (Nos. 14, 15) ; especially of the Holo- 

 ptychius from Scotland, and the Macropoma of the Chalk, 

 from Lewes in Sussex. 



HOLOPTYCHIUS. Wall-case B. (No. 14.) In this genus, the 

 scales, which are very large, are deeply corrugated, and the 

 bones of the head sculptured and granulated ; the teeth are 

 large, conical, and of great density ; the ventral fins are nearer 

 the tail than in the other ganoids ; some of the spines are of 

 great size. There are several large fishes of this genus from 

 Scotland, in the lower compartment of this cabinet, so striking 

 in their appearance, that they seldom fail to arrest the atten- 

 tion of the visitors. Of these, the Holoptyctiius nobilissimus, 

 from the Old Red Sandstone at Clashbinnie, near Perth, (pre- 

 sented by the Rev. James Noble,) is the most conspicuous. 

 This magnificent ichthyolite is figured in the splendid work 

 of Sir Roderick Murchison, " The Silurian System," PI. II. ; 

 it consists of the body and head, attached to the stone by the 

 dorsal aspect. The body is depressed, and measures twenty- 

 eight inches in length, and twelve in breadth. The head is 

 short and obtuse ; the lower jaw, the mouth, and the two 

 branchial rays or plates are exposed. The scales are large, and 

 strongly marked with undulating furrows } between the 

 ventral fins and the head there are but fourteen scales. The 

 tail is wanting. 



Holoptychius Flemingii, and If. Andersoni, are two species 

 of this genus which occur in the Devonian of Scotland; 

 and there are two large blocks of fawn-coloured sandstone 

 on which are seen lying in relief ten or twelve of these 

 beautiful ichthyolites, whose jetty black finely contrasts with 

 the hue of the surrounding stone. Many are from Dura 

 Den, near Cupar, Fifeshire, the locality where the Rev. Dr. 

 Fleming discovered the first recognised vestiges of this genus, 

 in 1830. 



Of the Holoptychius Hibberti, of the coal measures, whose 



