62 CONTEIBUTIONS TO CANADIAN PALEONTOLOGY. 



but presents little that is characteristic, the elevation of the transverse 

 anterior ridge being obliterated and. the frustra too faint to be represent- 

 ed. There are here, however, as in some of the other specimens, faint 

 signs of what appears to be a series of minute warts, probably the bases, of 

 spines situated on one side upon the anterior ridge, and some of the others 

 show possible marks of a second series a little above the base of the legs> 

 though this is by no means clear. 



ARACHNID A. 



Order Scorpiones. 



Mazonia Meek and Worthen. 



In his memoir on the Carboniferous scorpions of Scotland,* Mr. B. N. 

 Peach endeavours to show (p. 408-409) that this genus is identical with 

 Eoscorpius of the same authors, to which he refers all the Scottish species. 

 He endeavours to account for the absence of the smaller lateral eyes by ' 

 the overhanging of the cephalothorax in front, but while this would have 

 undoubtedly concealed the eyes along the anterior border, such an expla- 

 nation will hardly account for the absence of those at the sides behind the 

 anterior lateral corners, and Messrs. Meek and Worthen expressly state 

 that " the anterior lateral margins (particularly on one side) are well pre- 

 served." There is, moreover, another difference which should have some 

 weight, for the cephalothorax of Mazonia is broadest iniront and narrows 

 ' regularly though slightly backward, and is longer than broad ; while in 

 all the species of Eoscorpius yet discovered, though they have in general 

 the same subquadrate form, the reverse is true, the base being enlarged 

 considerably, so that the anterior is distinctly less than the posterior 

 breadth, and the basal breadth is greater than the length ; and since in 

 Cyclophthalmus, more satisfactorily distinguishable from Eoscorpius by 

 the definitely different arrangement of the smaller eyes, the cephalothorax 

 is broadest in the middle and narrows in both anterior and posterior 

 directions, it seems probable- that when we discover the arrangement of 

 the eyes in Mazonia, we shall detect something further and more satis- 

 factory to distinguish the genus and that hence, pending discoveries, it is 

 well not to relegate it to the same immediate group as Eoscorpius. 



This conclusion seems the more reasonable when we state that there 

 occur among the sigillarian relics imperfect remains of a scorpion which, 

 though the anterior lateral margins are imperfect, shows just these same 

 characters of the cephalothorax, which is longer than broad, is broadest 

 anteriorly, and narrows gently and regularly toward the base. It seems 

 better, therefore, until further light is thrown upbn Mazonia to regard it 



*Trana. Roy. Soo. Bdinb., xxx., 397-412, pi. 22, 23. 4°. Edinburgh, 1882. 



