PLATE 5. 



Fig. 1. 401. 6. BuTHOTREPHis GRACILIS. (Pag- 18.) 



1 a. A small delicate specimcu of tliis si)ecies The engvaving represents the branches rather too slender and 



acute. 

 1 b. An elongated stipe with numerous branches. 

 1 c. A fragment with several branches which are again subdivided. 



1 d. A large individual having fewer branches in proportion to its size, than the preceding, and approximating 



iu cliaracter to the succeeding forms. 



Fig. 2. 402. 7. BuTHOTREPHis gracilis, var. intermedia. ( Pag. 19.) 



2 a. A slender specimen with few branches. 2 6. A more rigid specimen with numerous blanches. 



Fig. 3. 403. 8. BuTHOTREPHis gracilis, var. crassa. (Pag. 19.) 



3 a, h, c, are common forms of this species in its proper and coarser varieties. 



•3 d. A large specimen, with the branches extremely diverging and mostly simple. 



