Jakob E. Lange: Studies in the Agarics of Denmark. II. 33 



I deem their transference to Coprinus a decided systematic 

 improvement. 



Other microscopic features are of importance for the 

 determination and classification of the several species: 



Spore-colour. — While the rusty-spored Coprini are generally 

 set apart in a special genus, Bolbitius, the attempt to single out 

 the species with snuff-brown sporepowder as a special genus or 

 subgenus (Coprinopsis Karst.) has not met with general approval. 

 In fact all shades from pitch-black to brown are represented, 

 and it is consequently almost impossible to draw a clear boun- 

 dary-line. The same may be said of the colour of the individual 

 spore (sub microsc). It varies from pale date-brown transparency 

 to almost pure coal-blackness. The colour of the (ripe) spore 



*• 



« b 



I. n. 



I. Surface of Copr/nus-gill. — II. Spores of C. plicatilis. 750 : 1. — 

 III. Spores of C. narcoticus. 750:1. 



seems to be very constant and consequently is a good specific 

 character, even if it cannot be used with profit for subdividing 

 the genus. 



The outline and size of the spores vary considerably 

 within the genus. The spores of the Coprini are generally 

 rather large; spores less than 8 x 5 (i are rare; in most species 

 the average length is 10— 13 ja, but some few species have 

 almost gigantic spores, especially C. sterquilinus, whose spores 

 average 19 x 12 |u. — In most cases the outline of the spore is 

 oval or subovate, but some species have lemon-shaped or sub- 

 cordate (triangular-subrotund) spores. These latter have a wart- 

 like apex and a somewhat truncate base and are (always?) 

 somewhat flattened, thus showing a different outline when 

 viewed from the side or the front (fig. II). This may lead the 

 uncautious observer to the erroneous conclusion that the spores 

 are biform. In all the species observed the spore-membrane is 

 smooth; granulate spores like those figured by Ricken (Coprinus 



