156 ENDOSPORE.E. [ALWISIA. 



of numerous irregular, tubular threads, 0'5 to 1 mm. long, 3 to 

 18 /x wide at their origin at the apex of the sporangium, whence 

 they radiate downwards, tapering and branching at a wide angle 

 below, the slender extremities attached to the wall about half- 

 way down the sporangium ; pale red, beset with minute scattered 

 papillae. Spores pale red, closely reticulated over the greater 

 part of the surface, the remaining part loosely reticulated, 5 to 6 

 fji diam. Mass., in Journ. R. Micr. Soc. (1889), p. 349. Trichia 

 frayilis Host., Mon., App., p. 39 (in part). Prototrichia Bombarda 

 Mass., Mon., p. 128. 



Plate LVIIL, B. a. clusters of sporangia, x 2 ; b. cluster of sporangia, 



x 20 ; c. immature sporangia, from a mounting in glycerine, showing, 



through the walls, the capillitium threads arising from the apex of the 



sporangium, x 20 ; d. fragment of upper sporangium-wall, from which 



three capillitium threads proceed, only a small part of the thread shown, 



x 280 ; e. fragment of sporangium- wall to which the lower end. of a branching 



capillitium thread is attached, x 280 ; /. spores, x GOO (Ceylon). 



This species is represented by a single gathering in July 1868 by 

 Thwaites from Ceylon. The sporangia are to a large extent immature, 

 purplish, and with the spores imperfectly developed, but a few are 

 nearly mature and show the rufous-brown colour described above. 

 Although the character of the long clustered stalks is peculiar, the 

 colour and texture of the sporangium-wall, and the colour, size, and 

 markings of the spores are similar to what is seen in other members 

 of the TubulineoR, while the threads of the capillitium find a close 

 analogy in the tubular extensions of the sporangium-wall of Sij)ho- 

 ptychium. 



TLib. On Jungermannia, growing on decayed wood. Gongolla Forest, 

 Ceylon (B. M. 1000). 



Order IV. RETTCULARIACE/E. Sporangia combined into an 

 jethalium ; sporangium -walls incomplete, perforated, or forming a 

 spurious capillitium. 



KEY TO TILE GENERA OF RETICULARIACE.E. 



Sporangium-wall cap-shaped at the apex, continued down to the 

 hypothallus in four to six straight threads. 



(30) DlCTYDLETHALTUM. 



Fig. 38. Dietydiathalium plumbeum Host. 



a, ^thalium. Natural size. 



b. Eight sporangia of an gethalium isolated ; in 



three the column of spores has fallen away, 

 leaving the cap and persistent threads. Mag- 

 nified 20 times. 



