50 Froccedings of the Royal Physical Society. 



belief tliat they were attached by a byssiis to sunken or 

 floating timber." * Conclusive and remarkable confirmation 

 of this view has lately come under my notice. My colleague, 

 Mr H. Woodward, LL.D., called my attention to a specimen 

 of a plant resembling a Calamite, from the Millstone grit of 

 Lancashire, compressed quite flat in shale, with a number of 

 these Antliracopterm so placed around the wood, that no other 

 supposition than that of attachment by a byssus will account 

 for their position. 



A very characteristic species of the Middle Coal and Iron 

 series occurs in the Bo'ness coalfield,-|- and is quite distinct 

 from those of the English Coal Measures described by Mr 

 J. de C. Sowerby. It is shorter, thicker, and with a greater 

 convexity of valve. 



The presence of Anthracoptera has now been pretty well 

 demonstrated in the Wardie Shale group of the Calciferous 

 Sandstone series, J through the collecting of Mr James 

 Bennie and Mr J. Henderson. Throughout its distribution 

 the genus retains its distinctively brackish or fresh-water 

 habit, whilst the shells of certain of its species appear to have 

 been a great habitat for the little tubicolar Annelide Spirorhis. 

 The infested condition of such Mollusca by these little worms 

 appears to have been pretty general, for they are found 

 adhering to them both in the Lower Carboniferous of the 

 Edinburgh district and Ayrshire. § 



The systematic position of Anthracomya is less certain. 

 To Salter, who established the genus, II its affinities were 

 evidently a question of doubt, but I strongly suspect it 

 cannot be very far removed from Anthracoptera. Only one 

 species (as yet described) occurs in Scotch Carboniferous 

 rocks. It is confined to the Coal Measures, and the Middle 



* Acadian Geology, p. 203. 



i A. tumida (Etlieridge), Mem. Geol. Survey, Scot!., Expl. 31, p. 82. 



Ij: Ethcridge, "On the Invertebrate Fauna of the L. Carboniferous Series of 

 the Edinburgh Neighbourliood," etc. (Quart. Jour. Geol. Soc, 1878, xxxiv., 

 p. 1). 



§ J. Young, "On Organisms from the Calciferous, or Cement-stone Series 

 lying at the base of the Carboniferous System in Ayrshire" (Proc. Glasgow 

 Nat. Hist. Soc, 1878, iii., pt. 3, p. 328). 



II Iron Ores of Great Britain, 18G1, pt. 3, p. 229. 



