The natural order Gio'artiiiaceiT' iiicliules nine British 

 ft'enera. namely, ('hoiuJri\ii. (iii/ajiiiKi, Plnjllophord, Stcno- 

 {iraninw, Gi/»nioii<)n(irti.s, Alinfeltia, Actinococcus, Callo- 

 pJij/llis and lastly Ccdli/iuciiia. Of these the representa- 

 tives are all fairly well developed plants, with the excep- 

 tion of the species belonging- to the genus Aefinococcus. 

 One of these has been shown to lead a parasitic life on 

 Pli j/U<>p)i ora Brod 'ue i. 



The genera Choiidriis and Gif/artina differ from the 

 remaining members of the Gigartinaceae in their structure. 

 They show internally a very well marked hyphal arrange- 

 ment of the cells — their internal tissues in the younger 

 plants consisting of fairly loose filamentous cells. The 

 central tissues of the othei' genera are, with the exception 

 of Aetin<)eoccu:<, far more compact and psendoparenchy- 

 niatous. The species of Chondnis have a flattened plant l)ody 

 or thallus. The carpospore^ in the fruit or cystocarp are not 

 surrounded by any special fibrous integument. The latter 

 is one of the distinguishing features of the species of the 

 genus GIf/arfina. 



('ho)idriis crispiis is the only species of its genus 

 occurring in British waters, and therefore in the L.M.B.C. 

 district. Quite a large number of varieties are dis- 

 ting-uished, but I have not referred to these in this memoir, 

 as I consider their recognition to be of no general value. 



The s:^nus Chondnis was founded bv Stackhouse — the 

 name crispiis was given to the species by Linneeus. The 

 latter, however, placed the species in the genus Futiis, to 

 which he referred almost every seaweed. Stackhouse 

 removed the species, and gave it a place in the genus 

 Ghondrus, where it has remained ever since. Its name 

 therefore runs thus: ('lioiidni>i cri^jnis (L.), Stackh., or, 

 according to a certain number of German Algologists, 

 Gfiondrus cr/spiis, L. sp. They wish to indicate merely 



