INTRODUCTION TO CRYPTOGAMIC BOTANY. 407 



tinct ej)iderinal cellular coat. • Collema is thus closely con- 

 nected with Leptogium, which is further distinguished by its 

 marginate disc. The gonidia differ very much from those of 

 other Lichens. In Collema and its closer allies, they are 

 minute and arranged in moniliform rows ; but in Synalyssa 

 they resemble those of Faulia (Fig. 84-, a), arising from the 

 fissiparous division of each gonidium, accompanied by a bifur- 

 cation of the supporting thread ; while in Oniphalaria (Fig. 

 86, e, f) their generation resembles that of Hwimatococcus. 

 The fact was first noticed, I believe, by Montague, under 



f t^ ^J^ 





Fig. 86. 



a. Stylospores o{ Abrotkallus Sinithii, Tul. From specimens gathered 

 at Craigie Hill by Dr. Lindsay. 



b. Synalyssa vulgaris. From specimens gathered at Bristol by Mr. 

 Thwaites. A portion of the plant with its fostigiate fruit and palmel- 

 loid, gonidia one of which is represented more highly magnified in the 

 act of division. 



c. Asci, sporidia, and paraphyses of the same. 



d. Hoematococcoid excrescences which roughen the thallus. These 

 are tinged with red. 



e. Hsematococcoid gonidia of Oniphalaria nummularia, Mont. From 

 an Algerian specimen given to me by Dr. Montague. The upper cell 

 is darker than the rest, being near the surface. 



/. Filaments of medullary tissue, forming meshes as in Omphalaria 

 Girardij two cells of the cuticle, and ascus with sporidia and para- 

 physes. 



All moi'e or less magnified. 



