16 6 Proceedings of the Royal Irish Academy. 



Ulothrix moniliformis Kiitz — I. 



subtilis Kiitz.— S, cell 8/x lat., 5fi long. ; C. 



var. variabilis (Kiitz.) Kirchu.— L, 0, Ac, I, CI, B, W, CP. 



var. tenerrima (Kiitz.) Kirchn. — W, Mw. 

 tenuis Kiitz. — C ; D, 15-17/u. broad, 4fi long, from several places. 

 zonata (Web. et Mohr) Kiitz.— C, L, VL, CI, Ac. 



Hormospora ELLIPSOIDEA sp. nov. — H. lobulis subangustis, solitariis, et 

 subtlexuosis ; cellulis approximatis seel demuni subdistautibus, 

 diametro circiter 1-^-plo longioribus, polis rotundatis, 10"5-ll'6/i long, 

 7'5-8'3/x lat., tubul. 15-5-16'5/x lat. D. 

 *Binuclearia tatrana Wittr. — C, in many places, usually from 7-!)/u broad ; S ; 

 CP, up to 11 fi broad ; Cn. 



Fam. Chaetophoraceae. 

 Chaetophora pisiformis (Roth) Ag. — C. 



elegans (Roth) Ag. — C. 

 Myxonema amoenum (Kiitz.) Hazen. — D. 

 protensum (Dillw.) Hazen. — SL. 

 nanum (Dillw.) — C. 



fastigiatum (Kiitz.) Hazen. — C, SL, LG, Ac. 

 tenue (Ag.) Hazen. — S, CP. 



Fam. Microthamniaceae. 

 Microthamnion Kuetzingianum Nag. — C; D, 3-3-5/u broad, 14-17/x long. 



Fam. Trentepohliaceae. 

 Trentepohlia Iolithus Wallr. — Cliffs of Croaghmore. 

 aurea (L.) Mart. — W, C, D, Cliffs of Croaghmore. 

 lichenicola (Ag.).— L, up to 10-12/x broad, zoosporangia 16-20ju. 



Order ULVALES. 

 Fam. Ulvaceae. 

 Enteromorpha intestinalis (L.) Link. — C, frequent in quite fresh water. 



Order SCHIZOGONIALES. 

 Fam. Prasiolaceae. 

 Prasiola parietina (Vauch.) Wille.— L, W, C. 



Order MICROSPORALES. 

 Fam. Microsporaceae. 

 Microspora abbreviata (Rabenh.) Lagerh.— C, cells 11-12/u. broad, H times 

 longer than broad, average size ; Cn, breadth 10-llu. 



