Clare Island Survey — Marine Algae. 15 121 



Myrionema saxicolum Kuck. 

 Some very beautiful specimens of this rare plant were found on limpet- 

 shells on Clare Island in October, 1910. The sporangia and filaments were 

 slightly larger than in the Heligoland material, but Dr. Kuckuck tells me it 

 is undoubtedly the same species. 



M. reptans Fosl. 

 (= Ectocarpus reptans Crouan ; Ascocyclus reptans Eeinke ; Phycocelis reptans 

 Kjellm.; Chilwnema reptans Sauv. ; Hecatonema reptans Sauv.; Hecatonema 

 fucicola, Kylin). 



Though no one has thrown more light on the Myrionemaceae than 

 Professor Sauvageau, a few alterations with regard to his " Memoire " have 

 been found necessary. The present plant proves to be a Myrionema, and not 

 a Chilionema ; hence Foslie's name is restored. It is frequent in the south 

 of England on Fucus spp., but is apparently rare in Co. Mayo, having been 

 searched for on many occasions, but found once only. 



Ulonema rhizophorum Fosl. 



It is most probable that Ulonema is merely a form of M. strangulans 

 occurring on Dumontia, but some curious stages occasionally found make one 

 hesitate to reduce it till the point has been more thoroughly investigated. 



Hecatonema reptans Kylin (= Ectocarpus reptans Kjeilm., non Crouan) ; 

 Streblonema reptans De Toni). 



The full synonymy of this species and M. reptans will be given in the 

 Monograph. Suffice it to say here that I have examined Kjellman's type, and 

 there is no doubt that it should be placed in Hecatonema. It is not 

 uncommon in our district on Claclophora sericea and C. rupestris. 



H. speciosum Cotton, comb. nov. (= Myrionema speciosum Borg. ; Hecatonema 



diffusa in Kylin). 



The type-specimens of both these plants have been examined ; and it is 

 quite clear that H. diffusurn Kylin is an early stage of Borgesen's M. speciosum. 

 Hecatonema is, however, the most suitable genus. The plant is common in 

 the British Isles, especially in spring, and was noted frequently in Clare 

 Island on a variety of plants during both the April trips. 



Mierospongium globosum Pieinke (= Myrionema globosum Fosl. ; Hecatonema 



gldbosum Batters). 



A difficult species to place ; but when well grown it is evident that it is 

 most suitably located in the genus Mierospongium. 



Jt.J.A. peoc, vol. xxxi. Q 15 



