224 INTRODUCTION TO THE STUDY OF FUNGI 



as representing Aulographium, with coloured sporidia. The 

 Fhaeophragmiae is the largest section in this subfamily, having 

 six genera and a large number of species. The genera are 

 arranged in two groups, in one of which the lips of the peri- 

 thecia are obtuse and rather distant, and in the other acute 

 and connivent. In the former is placed Tryblidiella, already 

 mentioned as a triseptate condition of Tryblidium and Hysterium, 

 the typical genus, in which the lips are so connivent that the 

 disc is rarely exposed, except when moist. The perithecia are 

 carbonaceous and even, with three - septate or multiseptate 

 coloured sporidia. Corresponding species, with sporidia un- 

 coloured, have been transferred to the genus Gloniella, and 

 species with muriform sporidia to Gloniopsis and Hystero- 

 graphium. The third genus of Phaeophragmiae is Rhytid- 

 hysterium, in which the perithecia are striate or sulcate, and 

 resemble a Lichen without a thallus. Hitherto the genus is 

 confined to South America. In one other genus of the first 

 division the asci are polysporous, and Baggea has but one species, 

 which has been found in Northern Europe. The two remain- 

 ing genera, which constitute the division with thin connivent 

 lips, are Mytilinidion and Ostreion. In the former the asci are 

 octosporous and in the latter tetrasporous. Mytilinidion has the 

 perithecium, in typical species, vertical and compressed, after 

 the manner of Lophium, with the lips very acute, and firmly 

 closed. The other genus, Ostreion, originally denominated 

 Ostreichnion, but, as we think, unwisely changed for insufficient 

 reasons by Saccardo into Ostreion, has perithecia which in form 

 resemble an oyster, placed vertically, and resting on the hinge. 

 The sporidia are four in each ascus, which, in the only recog- 

 nised species, are very large and multiseptate. The sixth 

 section is Hyalophragmiae, in which the multiseptate sporidia 

 are hyaline. As already intimated, Gloniella is analogous to 

 Hysterium, with hyaline sporidia, and consequently the peri- 

 thecia are carbonaceous ; but in Pseudographis the perithecia 

 are coriaceous, and gaping, with precisely the habit of Try- 

 blidium and Tryblidiella. Arranged according to natural 

 affinities, these three genera would be consolidated, and the 

 three forms of fruit recognised only as subgeneric distinctions. 

 The genus Dichaena approaches Lichens in its habit of growing 



