﻿Ncmatopliyton crassum. 153 



Clarke, showed tliat this plant was referrable to N. 

 crassum, but that it had been highly altered by crystalli- 

 zation/ More recently, material collected by Prof. C. S. 

 Prosser from the Hamilton group of New York, furnished 

 specimens much more perfectly preserved, but yet much 

 altered by crystallization.^ From this it is to be observed 

 that the excellent state of preservation of the material 

 now at hand, afibrds excellent opportunities for verification 

 of the previous diagnoses." 



The cells of the Medulla are large, ranging from 

 40 fi-62 fi. broad, but are chiefly rather uniform in size, and 

 average about hQ ^. in diameter. This, it will be observed, 

 is rather larger than observed in former specimens of this 

 species, which showed a range of 23 ^.-46 ^. in one case^ 

 and 32 ^.-39 ^. in another."^ 



The entire structure is rather lax — not so much so 

 as in N. laxum and N. Ortoni, but closely comparable 

 with previous specimens of N". crassum. Medullary spots 

 are numerous and irregularly distributed. They are of 

 an irregularly rounded or oblong form, and appear to 

 range from 174 ^. to 261 ^. in diameter. Here and there 

 they seem to have undergone exceptional alteration 

 leading to the formation of spherical cavities about 436 ^. 

 in diameter. They are, however, in most cases, occupied 

 by a somewhat loose plexus of hyph?e having a somewhat 

 variable diameter, ranging upwards from 4.68 //. — similar 

 in general character and size to the hyphae lying between 

 the large cells of the medulla. 



Even without the aid of a magnifying glass, a certain 

 •concentric structure with broad zones is apparent in 

 the transparent section, but this is by no means as clearly 

 defined as in N. Logani. Under a magnifying power 

 •of moderate strength, this appearance entirely disappears, 



1 1. c. VII., iv., 25. 



2 Proc. U.S. Nat. Mus., XVI., 116, 



3 Proc. U.S. Nat. Mus., XVI., 116. 



i Trans. R. Soc. Can., VII., iv., 20-23, 20. 



