riilyctainaspis, a New Genus of Coccosteicla}. 227 



also a product of peat bogs. Whether we succeed in "sampling" 

 the Fairbairn exhalations or not, the circumstances of the 

 case at least suggest an easy method of collecting bog gases in 

 the future. I have heard of a Glasgow Professor of Chemistry, 

 in the early part of the century, I believe, who was in tlie 

 habit of taking the members of his class out with him into 

 boggy ground armed with bottles to catch the bubbles as they 

 rose in silvery little chains from the bottom of tlie pools. 

 But here we have suggested a simpler method. The bubbles 

 can be carried home in the ice, immersed in warm water, and 

 collected on liberation. 



XXIV. On Phlyctsenaspis, a neiv Genus of Coccosteidse.^ By 

 Dr K. H. Tkaquair, F.Pt.S., F.G.S. [Plate XII.] 



(Read 15tli January 1890.) 



In the Geological Magazine for this month (January) I 

 proposed to establish the genus Phlycta^nius for the peculiar 

 Coccostean from the Lower Devonian beds of Campbelltown 

 in Canada, named by Whiteaves Coccosteus Acadicus. In this 

 paper I propose describing that form more in detail, along 

 with an allied, though at the same time very strongly marked, 

 species from the Lower Old Pted Sandstone of Herefordshire, 

 to which on that occasion I also referred. The name Phlyc- 

 tcenius having been found to be pre-occupied, I have altered 

 it to Phlycta^naspis} 



Mr Whiteaves apparently did not recognise the extent of 

 the differences between this species and the true Coccosteus of 

 the Scottish Old Eed ; but this I think he would have done, 

 had he succeeded more thoroughly in deciphering the arrange- 

 ment of the plates of the cranial buckler. As it is, he seems 

 almost to hesitate as to whether it is specifically distinct 

 from Coccosteus cicspidatus of Agassiz. " In some respects," he 

 says, " the Campbelltown Coccosteus very closely resembles 

 the C. cicspidatus of Agassiz, but in others there are such 



^ Appeared also in the Geological Magazine, Decade III., Vol. YIL, No. 308, 

 p. 55, February 1890. 



- The name Phhjdmnius was used in the paper as read before the Society 

 and printed in the Geological Magazine. It was altered to Phhjcta:uaspis in 

 a note published in the same magazine for March 1890. 



