RHADINICHTHYS MONENSIS. 139 



fin ; these are clearly imjointecl and show that, as is characteristic of the genus Bhadi- 

 nicldhyH, the priiicij)al rays of this fin were unarticulated till towards their terminations. 



The ordinary length of this species seems to have been from 3 to 3^ inches. 



Mr. E. D. Wellbnrn has, in his paper in the ' Geological Magazine ' for June, 1900, 

 given a description of remains of this species, likewise fragmentary, from the Coal 

 Measures of Yorkshire, in which the details given above are corroborated. The text- 

 figure which accompanies his remarks, and to which I have already alluded, shows a 

 small fish wanting both head and caudal fin, but showing the dorsal, the anal, and some 

 remains of the ventral. In this s[)ecimen the dorsal fin is seen to^ be placed nearly 

 opposite the anal, though commencing slightly in front of it. Concerning the scales 

 Mr. Wellburn also makes the following remarks, which I take the liberty of quoting : 

 " In different individuals the scale-sculpture shows very considerable differences as 

 regards the strength and prominence of the scale-markings, the sculpture being much 

 more pronounced in the case of some individuals than in others, where the scales seem 

 almost smooth. Another point of interest is, that in the young fish the ventral scales do 

 not appear to be so low and narruw as they are in the more adult fish." 



Observations. — \) e must await the discovery of more perfect specimens before a com- 

 plete description of this species can be given. Meanwhile it is certain that its generic 

 position is in Rhadinicldhijs, and that among the species reckoned to that genus it comes 

 nearest to Rh. carinatus and Bh. canobiensis. In fact its scale-sculpture bears an 

 obvious resemblance to that exhibited by the usual type of flank-scale in the last-named 

 sj)ecies (see PI. XXX, fig. 2) — only the prominent transverse ridges are, in mone?isis, 

 nearly horizontal and only very slightly oblique in their direction (PI. XXXI, figs. 4, 5). 



Geological Position and Localities. — The remains q{ Bhadinichthp monensis, though 

 unfortunately mostly in a fragmentary condition, are pretty widely distributed in the Coal 

 Measures or Upper Carboniferous Rocks of Great Britain. The following localities are 

 recorded : 



North Wales : The original scales, now in the British Museum, were found by the 

 late Earl of Enniskillen in the Island of Anglesea. 



Staffordshire: Deep Mine Ironstone, Longton, and Woodhill Coal Shale, Park Hill 

 Colliery, Cheadle (J. Ward). 



Yorkshire : The following are given by Mr. E. D. Wellburn : In the Lower Coal 

 Measures: Halifax Soft-bed Coal, Shibden ; Halifax Hard-bed Coal, Queensbury; 

 Better-bed Coal, Low Moor and Wyke ; Black-bed Coal, Low Moor; Cannel Coal, near 

 Low Moor ; Crow Coal, near Leeds. In the Middle Coal Measures : Cannel Coal, 

 Tingley ; Haigh Moor Coal, Castleford ; Barnsley Thick Coal, Barnsley. 



Lanarkshire, collected by the Geological Survey of Scotland ; Newarthill, Royal 

 Scottish Museum. 



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