THE COMATUS SUB-TYPE 145 



contact with the flanges of adjacent gills. Before the expansion of 

 the pileus, the combined flanges of the gills form a continuous 

 cylindrical sheath just external to the stipe. 



(2) Cystidia are absent from the sides of the gills. In this 

 respect we have a marked contrast with the Atramentarius Sub- 

 type. 



(3) The interlamellar spaces between successive gills, which are 

 required to render possible the free development of the spores 

 on the hymenium, are secured not by cystidia acting as stays or 

 distance-pieces but, firstly, through the existence of the flanges 

 on the gill-edges, secondly, by an appropriate separation of the 

 gills where they adjoin the pileus-flesh, and thirdly, by the 

 gill-plates being sufficiently shallow and rigid. Here, again, we 

 have a marked contrast with what is found in the Atramentarius 

 Sub-type. 



(4) The basidia are dimorphic. They are of two lengths, long 

 and short. In this character there is an agreement with most of 

 the other Coprinus Sub-types, but a difference in respect to the 

 Micaceus Sub-type where the basidia are tetramorphic. 



Representative Species. — The Comatus Sub -type was founded 

 on Coprinus comatus, but it includes at least one other species, 

 namely Cojirinus sterquilinus. There can be little doubt that these 

 two species are genetically very closely related to one another. 

 Not only do they agree in the characters just given, but also in a 

 number of others which are of subsidiary importance so far as the 

 mechanism for the production and liberation of spores is concerned. 

 (1) In both species the pileus, just before expansion, is cylindrico- 

 conical and closely covered with white scales. A fruit-body of 

 C. sterquilinus at this stage of development is very similar to a small 

 C. comatus. (2) Both have a long stipe encircled by an annulus ; 

 and the annulus, usually, is carried upwards during the elongation 

 of the stipe as part of the base of the cylindrico-conical pileus and 

 then dropped upon the stipe at the moment that the pileus begins 

 to open out in a campanulate manner. (3) In both species the 

 stipe contains a thin axial strand of hyphae which runs freely down 

 the centre of its hollow chamber from the disc. (4) In both species, 

 the gills turn pinkish just prior to the ripening of the spores, owing 



VOL. III. L 



