THE GENUS CHITONIELLA. 117 



and afterwards almost plane ; it varies from seven to fifteen 

 centimetres in diameter ; the flesh is about 1 cm. thick in the 

 centre, and thins rapidly in the outer half. In the centre of 

 the pileus is a smooth brown or reddish-brown cartilaginous 

 patch, attached to the pileus in the middle but separated from 

 it elsewhere by a loose brown layer. This patch is 2-4 cms. 

 in diameter, generally split at the edges, but seldom entirely 

 broken up into separate scales. Elsewhere the cuticle of the 

 pileus is spht into ashy-brown or purple-brown, narrow, 

 re volute scales, and mingled with these scales are, as a rule, 

 radially arranged br^wn warts of varying size. These warts 

 are not always present ; they are formed from the loose tissue 

 which lies between the cartilaginous cap and the pileus, and 

 this tissue either remains in fragments on the pileus as it 

 expands or is retained beneath the unexpanding cap. The 

 greatest development of these warts appears to take place 

 when the agaric emerges during constant rain, and under these 

 circumstances the pui-ple-brown colouration of the scalea is 

 often wanting, so that the pileus is cream coloured or yellowish, 

 studded with brown warts. The margin of the pileus is 

 appendiculate. 



The volva at the base of the stem is r5-3 cms. high. In 

 young specimens it is slightly spreading, but m older examples 

 it is usually pressed close to the stem. The upper edge is 

 entire or irregularly lobed. In colour it is gray or purple-gray, 

 and generally it is quite loose and floccose. It differa alto- 

 gether in colour and texture from the cap which adheres to the 

 pileus. Very young specimens show that the volva is entirely 

 loose and floccose, and that the young pileus within it is 

 entirely covered by a brown cartilaginous layer. Dehiscence 

 of the volva takes place very early, when the agaric is less than 

 a centimetre high. The brown layer increases in diameter 

 with the pileus until it attains a diameter of 2-3 centimetres, 

 but it then separates from the latter, except in the centre, and 

 the pileus extends to a diameter of about 10 centimetres, 

 sometimes carrying with it in the form of warts part of the 

 looser tissue which separated it from the cap. The latter is 

 really the outer layer of the youn^ pileus. 



