Reports and Proceedings — S. Stafford and Warwick Institute. 381 



measuring 2 feet. Among fishes, the spiny acanthodian sharks, which 

 are typically Lower Palaeozoic, are still found in the Carboniferous 

 fauna, and are kuown to have been preyed upon by the higher fishes. 

 The pleuracanth sharks are characteristic of the period, and interesting 

 as showing a more generalized vertebi'ate skeleton than any later 

 fishes. The cochliodont sharks with grinding teeth appear to be 

 closely related to the existing Cestracion, but have many of the teeth 

 fused into extensive plates. Some of the sharp-toothed sharks also 

 seem to have had their teeth fused into rigid masses. The highest 

 fishes are the palaeoniscids and platysomids, which exhibit all the 

 fundamental characters of the present-day sturgeons, obscured beneath 

 a normal covering of ganoid head-plates and scales. Large dipnoan 

 fishes are numerous, and differ little from Ceratodus, except in showing 

 traces of the sepai'ate points of which their dental plates are composed. 

 Most important are the crossopterygian fishes, of which Rhizodas and 

 MegalicMhys are typical genera. These fishes make a closer approach 

 to the earliest lung-breathers than any fishes which have existed 

 before or since. Lung-breathers were certainly in existence just before 

 the beginning of the Carboniferous period, and all seem to belong to 

 a very primitive group of Amphibia, variously termed Stegocephalia 

 or Labyrinthodontia in allusion to the complete roofing of their cheeks 

 by bone and to the complicated structure of their teeth. In their 

 possession of supra-temporal plates and often of post-temporal bones, 

 as also in the marking of their superficial bones by the course of the 

 slime-canals, these amphibians more closely resemble fishes than any 

 later members of the order. Towards the end of the Carboniferous 

 period some of the smaller Stegocephalia, the so-called Microsauria, 

 seem to have passed into true reptiles very similar to the surviving 

 Sphenodon or Hatteria. 



III. — The South Staffordshire and Warwickshire Institute of 

 Mining Engineers. 



At the meeting on June 12, 1911, at the Council House, Walsall, 

 a paper " On the Carboniferous Limestone of Pair Oak, Cannock Chase 

 Coalfield", was read by Mr. George M. Cockin. 



The rocks underlying the Coal-measures of the Cannock Chase Coal- 

 field have been described as being Silurian Limestone. The condition 

 existing at AValsall, where the Silurian rocks may be seen immediately 

 below the Coal-measures, was supposed to continue further north, 

 and this was said to be the case at a bore-hole at No. 2 Pit, Cannock 

 Chase Collieries. 



A few years ago fresh light was thrown upon the subject by 

 the discovery of fossils belonging to the Lower Carboniferous or 

 Mountain Limestone upon the old spoil-heaps of ]S T o. 1 Trial Pit, 

 Fair Oak Colliery. The discovery formed the subject of a paper read 

 before the Geological Society of London in 1906. 1 



A number of new fossils have been found since that date, and it is 



1 " On the Occurrence of Limestone of the Lower Carboniferous Series in the 

 Cannock Chase portion of the South Staffordshire Coalfield," by George 

 Marrnaduke Cockin, Quart. Jour. Geol. Soc, vol. lxii, p. 523, 1906. 



