194 THE BOTANICAL MA GAZINE. [V oi. xxiv. No. 284. 



(Lindau 6) among Pyrenomycetinese. The perithecium sunk in 

 mesophyll, the lack of stroma formation, the presence of an 

 orifice of perithecium, and its short neck, the perithecium wall 

 consisting of thin walled plectenchymatous cells, the presence 

 of paraphyses point to the association of the present fossil 

 fungus with Pleosporiaceae (Lindau 6), hence the generic name. 

 The lack of spores makes it impossible to refer to any known 

 genus. 



I am much indebted to Professor Shirai of the College of 

 Agriculture, Imperial University of Tokyo, who has been recent- 

 ly investigating the fungi infecting Cry ptomeria japonic a and 

 whose opinions on this fossil fungus gave a great help to the 

 study of this fossil. 



The specific name was given in honour of Professor Shirai- 



Diagnosis :— 



Pleosporites Shirainus gen. et sp. no v. 



Hyphae well developed, septate, 2-5 fi in diameter. Peri. 

 thecium, formed under the hypoderma of the leaves of the 

 host, well defined, spherical or somewhat flask-shaped, with 

 an orifice, short necked, thick walled, the wall consisting of 5— 

 7 or more irregular layers of thin walled plectenchyma cells. 

 Asci formed at the bottom of perithecium, without development 

 of stroma ; paraphyses present. 



Host : — The shoot of Crypto meriopsis. 



Locality : — Upper Cretaceous, Hokkaido, Japan. 



On concluding this paper, I wish to offer my sincere thanks 

 to Professor Fujn for his kind advice and criticism throughout 

 the work, and for the materials which he has generously put 

 at my disposal. 



