HARD WI CKE'S S CIENCE- GO SSI P. 



•71 



the law which called the Peronosporites into 

 existence countless ages ago is in force now, and 

 that this law produces tlie same results now 



as then." 



CHAPTERS ON 



CARBONIFEROUS POLYZOA 



By G. R. Vine. 



Chapter IV. and Last. 



T' 



Fig. 204. A Fossil Fungus [Ptronn^/iorites antiquayius) with its 'Mycelium growing amid the vascular 

 bundles of a Lepidodendron from the Coal measures (enlarged 250 diam.). 



*HE Glaucoitonij 

 of the carbon- 

 iferous era comes next 

 to the FcncstcUa in 

 number of species and 

 in the variation of 

 pattern amongst the 

 individuals of the 

 several species. The 

 genus was established 

 by^ Gold fuss, and re- 

 vised by Lonsdale, 

 but so insufficiently 

 characterized by 

 M'Coy in his work 

 on the Carboniferous 

 Fossils of Ireland as 

 to be scarcely of any 

 advantage to the stu- 

 dent. His description 

 is, ' ' stem elongate, 

 oval, laterally branch- 

 ed ; obverse, bearing 

 longitudinal rows of 

 pores ; reverse, stri- 

 ated;" — a description 

 sufficiently exact when 

 you know the genus, 

 but useless to a large 

 extent when you do 

 not. " The oval form 

 is not universal ; and 

 the omission of any 

 reference to the form 

 of the cells has led to 

 the inclusion under 

 one generic designa- 

 tion of forms which 

 should at least rank 

 as sub-genera."* 



The Glaiicononic 

 seems to have come 

 into existence in the 

 Upper Silurian era ; 

 but the one solitary 

 species of the genus 

 given in Morris's Cata- 

 logue is veiy insuffi- 

 cient data on which 

 to found an argument 



* Prof. J. Young and 

 Mr. John Young. Pro- 

 ceedings of the Nat. His. 

 Soc. of Glasgow, March, 

 1875. 



