2o8 



ALG^ 



frequently divide into only two tetraspores. The conceptacles are not 

 unfrequently surmounted by singular horn-like processes. Melobesia 

 produces peculiar branching septated gemmce. 



Literature. 



Rosanoff — Mem. Soc. Sc. Nat. Cherbourg, 1866. 



Areschoug — Observ. Phycol., iv., 1875. 



Solms-Laubach — Die Corallinenalgen d. Golfes Neapel, 1881. 



The greater number of our red seaweeds belong to the following 

 orders, established by Agardh, the boundaries of which are not in all 





Fig. 185. — Chondnis crispus Stackh. a, with cystocarps (natural size); h, uppermost portion of 

 frond with tetrasporanges (natural size) ; c, section through the frond and a portion of the cystocarp 

 (x 100). (After Kutzing.) 



cases well defined, and in regard to many of which much ^et remains 

 to be discovered as to their mode of reproduction, viz.: — Cryptonemia- 

 cEjE (Nemastoma, Ag., Grateloupia, Ag., Halymenia, Ag., Dumontia, 

 Lmx., Cryptonemia, Ag., &c.), Gigartinace^e (Chondrus, Grev., Gigar- 

 tina, Lmx., Kallymenia, Ag., &c.), Rhodymeniace^ (Rhodymenia, 

 Grev., Chylocladia, Grev., Plocamium, Lmx., Hydrolapathum, Rupr., 

 &c.), DELESSERiACEiE (Nitophyllum, Grev., Delesseria, Lmx.), Sph^ro- 

 coccacEjE (Sphserococcus, Stackh., Gracilaria, Grev., &c.), Hypn^ace^e 



