Vol.].] Reed. — Two New Ascomycetous Fungi. 145 



scattered groups of algal cells, also single algal cells somewhat 

 smaller than normal, often flattened and always separated by 

 deeply pigmented mycelial liranches. Just below the algal 

 cell is a dense pseudoparenchyma also deeply pigmented, while 

 beneath this is a thick layer of colorless parenchyma which 

 completely surrounds the cavity on all sides. Within this is the 

 innermost lining of the perithecial cavity, a thin walled proto- 

 plasmic subhymenial layer from which the asci develop. The 

 transition from the mycelial filaments to the pseudoparenchyma 

 layer is almost imperceptible. The mass of mycelial threads in 

 the medulla appear as if they had been divided in the center and 

 pressed outwards to form the sides, where they have fused and 

 interwoven in forming the walls about the asci. On the sides 

 of the perithecium the medullary filaments are again intertwined 

 and follow their normal course until again interrupted by the 

 development of another perithecium. The perithecium projects 

 on both surfaces of the frond, but projects farthest on the ostiole 

 or apical side. The ostiole gradually develops after the perithe- 

 cium begins to mature, and probably is formed by a dissolution 

 of the perithecial walls after their formation, and near the time 

 of the maturity of the spores. There is a small canal from the 

 inner cavity to the outer opening or ostiole. This is lined and 

 surrounded at the inner opening by fine, colorless hairs. The 

 ostioles are on either surface of the frond, as some perithecia 

 open on one side and some on the other. 



The inner wall of the perithecium consists of one layer of 

 cells, flattened tangentially, thin walled and protoplasmic. This 

 is the subhymenial layer from which the asci are developed. 

 The layer next to this is five or six cells deep, has thin walls also 

 flattened tangentially and often pointed at the ends. The outer 

 layer of pseudoparenchyma has much larger, thicker walled cells, 

 slightly or not at all flattened, pigmented very deeply for several 

 cells in depth on the upper and lower surfaces, and slightly 

 pigmented on the sides within the medulla. The pigmentation 

 occasionally extends entirely around the perithecium and into 

 the subh.ymenial layer. The pigmentation varies greatly even 

 in the perithecia of the same frond, both in the thickness and 

 regularity of the layer. This layer seems to be formed by the 



