112 Proceedings of the Royal Physical Society. 



other in all particulars. Fig. 16a gives a corresponding 

 view to that of the spore of >S'. caulescens, ' PL VI., Fig. 22a, 

 where the zone is entire and solid. Fig. 16c corresponds to 

 the enlarged portion of the zone of S. caulescens, Fig. 22h. 

 The remarks made on the structure of Trilctes XVI. apply 

 equally to Triletes XVII. On Triletes XV., of which we 

 have only seen a few examples, the zone is more divided 

 than in Triletes XVI. or XVIL, but the peripheral portion 

 of the zone is usually united into a more or less solid margin 

 (PL IV., Fig. l^d). On Triletes XIV. the zone is converted 

 into a fringe formed of much flattened simple or one or more 

 times divided hairs, placed closely together, in several series. 

 In all these cases, except Triletes XIV., the zone is referable 

 to Dr Eeinsch's sub-tribe Stichostelium, but in Triletes XIV. 

 it is probably referable to his sub-tribe Trichostelinm. 



From these considerations we have been led to unite 

 Eeinsch's Stelidem with the various Triletes on which they 

 occur. 



Triletes XIV. PL IV., Figs. 14a, 14&, 14c, 14c^, 14c, 14/. 



Disc of macrospore smooth, or very slightly granulated; 

 spore wall thick. Triradiate ridge very prominent, consider- 

 ably elevated, and occupying all the visible upper surface 

 when the zonal appendages are perfectly preserved. Zone of 

 several series of flattened hair-like filaments, which are 

 simple, or once or more times divided. 



This form is easily distinguished from any other with 

 which we have met by the stout disc and fringe-like zone. 



On many specimens the zone is so entangled in the matrix 

 that it gives the specimen the appearance as if it possessed 

 a swollen band through which the extremities of the hair- 

 like filaments project. Specimens, however, have been 

 secured showing the zone quite freed from the matrix (Fig. 

 146). On many of the specimens the zone has almost en- 

 tirely disappeared (Fig. 14a), or is present only in part (Fig. 

 14c). The position of the zone is not quite equatorial, but 

 extends from the extremities of the arms of the diverging 

 ridges to the periphery of the (compressed) spore. It is of a 



