2o8 



ALG^ 



frequently divide into only two tetraspores. The conceptacles are not 

 unfrequently surmounted by singular horn-like processes. Melobesia 

 produces peculiar branching septated gemince. 



Literature. 



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



Areschoug — Observ. PhycoL, iv., 1 875. 



Solms-Laubach — Die CoralHnenalgen 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 



a 



   .^ '^, 





Fig. \%s- — Cho7idrjts crispus Stackh. a, with cystocarps (natural size) ; b, uppermost portion of 

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

 (x 100). (After Kiitzing.) 



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

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

 CE^ (Nemastoma, Ag., Grateloupia, Ag., Halymenia, Ag., Dumontia, 

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

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

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

 &c.), Delesseriace^ (Nitophyllum, Grev., Delesseria, Lmx.), Sph/ERO- 

 COCCACE.E (Sphaerococcus, Stackh., Gracilaria, Grev., &c.), Hypn/EACE/e 



