ELONICHTHYS PECTINATUS. 87 



fin has its rays conformed in a manner similar to those in Gyrolepis, and the origin of 

 the dorsal fin is nearly opposite the commencement of the anal. 



The scales of E. pectinatus bear some resemblance in their external sculpture to 

 those of Acrolepis Hopldnsi, M'Coy {Gyrolepis Rankinei, Agassiz), but are at once 

 distinguishable by their comparative thinness, the narrowness of their covered area, their 

 posterior serrations, and the pectinated appearance of the posterior margin when seen 

 from the internal aspect. 



Judging from its size, its wide gape, and its formidable teeth, this magnificent 

 palaeoniscid must have been a veritable tyrant among its smaller contemporaries, and 

 had it been known to Agassiz or Egerton it would certainly have been classed as a 

 '■' Sauroid." 



Geological Position and Localities. — Only from the Lower Carboniferous rocks of 

 Scotland, and as yet principally olitained from those of the Forth Basin. The original 

 specimen was obtained from the Gilmerton Ironstone, near the base of the Carboniferous 

 Limestone Series of Midlothian, but subsequent collecting has extended our knowledge 

 of its geological range both downwards into the Oil Shale series and upwards into the 

 Upper Limestone Group. The horizons and localities in which it has occurred in the 

 east of Scotland are in ascending order as follows : 



Oil Shale Group : — In Ironstone nodules in the roof of the Dunnet Shale at Straiton, 

 near Kdinburgh ; also at West Calder, and Oakbank, near Midcalder ; Ardross, Fifeshire. 



Lower Limestone Group : — Gilmerton Ironstone, Gilmerton, near Edinburgh. 



Edge Coal Group : — Borough Lee Ironstone, Loanhead, near Edinburgh ; Denhead 

 Ironstone, Denhead, Fifeshire. 



.Upper Limestone Group : — Levenseat Limestone shale, Levenseat, Midlothian ; 

 South Parrot Coal Shale, Niddrie, near Edinburgh. 



In the west of Scotland I only know of its occurrence in the Crossbasket Ironstone, 

 East Kilbride, a specimen showing disjointed bones and scales of this species being in 

 the Coutts Collection in the Edinburgh Museum, and labelled as from this locality. 



logische Abhandlungeu,' vol. ii, pt. 2, Berlin, 1888. It is true that in 1877 (see p. 12 of the present 

 work, and ' Quart. .Journ. Geol. Soc.,' vol. xxxiii, pp. 567 — 571) I proposed to cancel Agassiz's genus 

 Gyrolepis on account of the diflBculty of defining a genus in the fragmentary Triassic remains 

 ordinarily referred to it, and which had been tlie subject of much difi'erence of opinion among 

 Continental palaeontologists. Since that time, however, the late Prof. Dames, in the above-quoted 

 memoir, has shown that the genus is perfectly tenable, at least, for certain Triassic forms, including 

 the typical O. Alberti, Ag. See also Dr. Smith Woodward's ' Catalogue,' pt. ii, p. 510. 



