ACROLEPIS HOPKINSI. | 
inches behind the origin of the pectoral, but is badly preserved, little more being seen 
of it than the stumps of its truncated rays. 
In Pl. XXV, fig. 6, is exhibited a specimen showing portions of three bands of flank- 
scales from the “ Drumgray ” Coal Shale, Carluke, Lanarkshire. It belongs to the 
Rankin Collection, Hunterian Museum, University of Glasgow, and is therefore very 
probably one of the original types of Gyrolepis Rankinei of Agassiz. ‘These scales show 
the typical Acro/epis-shape—the extensive covered area, prolonged upwards in a pointed 
process, and the deeply imbricating arrangement. ‘The sculpture of the exposed area 
consists, as before, of closely set, sub-parallel ridges, passing obliquely downwards and 
backwards across the surface, frequently intercalated, sometimes branching, and ending 
on the non-denticulated hinder margin. ‘hat the fish to which these scales belonged 
was of large dimensions is evident, the height of the exposed area being no less than 
$ inch, the breadth a little less, but I see no reason why it should not be referred to 
Acrolepis Hopkinsi. 
In 1877 I described a slab, from shale below the “ Main”’ Limestone of Braidwood, 
Lanarkshire, in the collection of the late Dr. Hunter-Selkirk, and showed a number of 
scales and bones of a large Acrolepis, which I referred to Acrolepis (Gyrolepis) Rankint, 
Agassiz, sp. ‘These remains seemed to show a character of their own, inasmuch as the 
head-bones presented more of a tubercular ornament than in the specimens above 
described, but I nevertheless cannot think it safe to found a new species on that 
character. ‘I'he ridges on the scales of the caudal region form a reticulated pattern by 
coalescence. 
Remarks.—The Lanarkshire specimens share with Hlonichthys pectinatus the tradi- 
tion of representing the Gyrolepis Rankinei of Agassiz, and of the two it is much more 
probable that the Acro/epis is the fish in question.’ In fact, as I have already remarked, 
the specimen of scales from Dr. Rankin’s collection, represented in Pl. XXYV, fig. 6, may 
be indeed the type specimen. Agassiz’s name is, however, merely a manuscript one and 
has therefore no authority, even if we had certainty on the subject, which we have not. 
And as I cannot find any positive mark of distinction between these Scottish specimens 
and those from Yorkshire and Northumberland, I must adopt M‘Coy’s name Hophinsi 
for all, 
Geological Position and Localities.—Acrolepis Hopkinsi occurs both in estuarine 
shales and in beds of obviously marine origin; it is also one of the few species of 
* Ganoids,” which are found both above and below the Millstone Grit. It occurs in: 
Lower Limestone Series: Braidwood, Lanarkshire. Cement Limestone Shale, East 
Kilbride. 
Millstone Grit: Hebden Bridge, Yorkshire. 
Lower Coal Measures: Kilmarnock Water; Newsham, Northumberland. 
1 “ Leeds,” however, is the locality given by Agassiz, ‘ Poiss. Foss.’; but “ Lanarkshire” is 
added by Morris, ‘Cat. Brit. Foss.,’ p. 328. 
