IN THE CARBONIFEROUS ROCKS OF THE EDINBURGH DISTRICT. 



705 



Transition Measures.— Mr Ward has given me the following list from those 

 North Staffordshire measures, now generally known as " Transition Series " : — 



Acanthodes, sp. 

 Ctenodus cristatus. 



Murchisoni, Ward (Ag., M.S.). 

 Diplodiis gibbosus. 



Megalichthys Hibbcrti. 

 Ccelacanthus elegans. 

 Elonichthys Egertoni. 

 sp. 



It will be seen that in this, the " Potteries," Coal Field, the great repository of fossil 

 fishes is the Middle Coal Measures, in which forty-eight species occur. But as of the 

 forty-eight no less than thirty-three are found also in the Lower Coal Measures of Scot- 

 land and Northumberland, including most of the common and characteristic forms, we 

 can hardly be said to have got into a new life-zone, so far as estuarine fishes are 

 concerned. 



In a paper " On the Fish-Fauna of the Yorkshire Coal Measures," published in 

 1901,* Mr E. D. Wellburn gives a list of seventy-eight species, a few of which are 

 queried, while some are given as new, but not described. As they stand, however, the 

 seventy-eight species may be tabulated as follows : — 



Occurring in the Lower Coal Measures, . . . .72 



Middle, . 

 „ „ Lower, but not in the Middle, 



„ „ Middle, but not in the Lower, 



Common to both Middle and Lower, 



44 



34 



6 



38 



And the thirty-eight species common to the 

 characteristic fishes known from the Lower and 

 the island. They are : — 



Pleuracanthtis Icevissimus. 

 „ cylindricus. 



Diplodics gibbosus. 



„ tenuis. 

 Petalodus Hastingsi. 

 Ctenoptychius apicalis. 

 Callopristodus pectinatus. 

 Helodus simplex. 



„ sp. 

 Pleuroplax Rankinei. 



„ Attheyi. 

 Sphenacanthus hybodoides. 

 Acanthodes Wardi. 

 Gyracanthus formosus. 

 Euctenius unilateralis. 

 Ctenodus cristatus. 

 Rhizodopsis sauroides. 

 Strepsodus sauroides. 

 sulcidens. 



two divisions comprise nearly all the 

 Middle Coal Measures in other parts of 



Megalichthys Hibberti. 



„ pyymaius. 



„ coccolepis. 



„ intermedius. 



CoslacantJms Tingleye/tsis, Davis. 



,, elegans. 



„ corrugatus, Wellb. 



Elonichthys Aitkeni. 



„ Egertoni. 



„ semistriatus. 



Acrolepis Hopkinsi. 

 Rhadinichthys Monensis. 

 Gonatodus Molynenxi. 

 Cycloptychius carbonarius. 

 Mesolepis Wardi. 

 „ scalaris. 

 Cheirodus granulosus. 

 Platysomus parvidus. 

 ,, Forsteri. 



Two of these, however, Ccelacanthus Tingleyensis, Davis, and C. corrugatus, Well- 

 burn (undescribed), are as yet known only from Yorkshire, while Petalodus Hastingsi 

 is a marine form characteristic of the Carboniferous Limestone of Armagh. 



* Proc. Yorhs. Geol. and Polytechn. Soc, vol. xiv. pp. 159-174. 



