THE GENUS CHITONIELLA. 115 



It will be seen that Hennings's description follows Berkeley's 

 closety, but was evidently taken from Saccardo, Sylloge 

 Fungorum, where the same mistakes are made in the conver- 

 sion of the stem measurements. These mistakes, which occur 

 also in the transcription of Psalliota pedilia, give a totally 

 erroneous idea of the stature of the fungus. It is a broad- 

 capped stout-stemmed agaric, and has not the resemblance to 

 such species as Chitonia rubiceps, Cooke and Mass., which the 

 substitution of millimetres for centimetres would give it. 

 Hennings was also misled by the fact that Berkeley assigned 

 it to Psalliota, and that Saccardo included it in Chitonia ; 

 from this he concludes that the spores are purple-brown, and 

 makes that a generic character. But Berkeley's specimens 

 were all immature, and, though their general aspect justified 

 their conclusion under Psalliota, he was not able to give the 

 colour of the spores. In one of the figures the gills are white, 

 but in the other two they are greenish. This is the normal 

 colour change, and the spores shed by fresh specimens are 

 invariably olive-green. Fortunately, there is only one species 

 of Chitoniella, and there is therefore no reason for burdening 

 the species with another name. 



The figures which accompanied Thwaites' specimens of 

 agarics were executed by Wm. de Alwis. They are extremely 

 accurate ; though as they were drawn from whatever specimens 

 came to hand, they are not in some cases typical examples of 

 the species they represent. Berkeley's descriptions of Ceylon 

 agarics are based almost entirely on these paintings. That 

 labelled Psalliota trachodes, B. (Thwaites, No. 911), is a half- 

 expanded specimen. The pileus is hemispherical, 7| cms. in 

 diameter at the base, and 5 J cms. high ; its colour is purple- 

 brown, corresponding with specimens recently collected in 

 fine weather, and it is rough, with darker warts and scales. 

 A dark brown cap remains on the top of the pileus, but it is 

 broken up, and therefore not typical. The base of the stem is 

 covered with soil and the remains of the volva to a height of 

 one centimetre, but no volva is depicted on the longitudinal 

 section. The gills are free, and the flesh of the stem and pileua 

 is reddish. Berkeley was evidently ui doubt whether this 



