16 22 Proceedings of the Royal Irish Academy. 



Staurastrum dilatatum Ehrenb. — C, average size 20'8/* long, 2L5/* broad ; D, 

 W, DL, LG ; Or, 23/;. long, 24/* broad. 

 *disputatum W. & G. S. West.— W. 

 *erasum Breb. — Plankton of LG, SL, and of EL. 

 furcatum Breb. — W. 



var. reductum W. & G. S. West. — C. 

 furcigerum Breb. — L, W. 

 gracile Ealfs.— C, L, Ac, K, W, CP, Cr. 

 var. nannm Wille. — W. 



var. cyathiforme W. & G. S. West. — Plankton of LG, breadth with 

 processes 69/*, length 40/* ; C ; SL, up to 88/* wide. 

 hexacerum Ehrenb.) Wittr.— C, L, DL, D, Cr, W. 

 Mrsutum (Ehrenb.) Breb.— SL, M, L; D, 31-6x25-26/*; C, average size 



44 x 44m; CP, 46/* long, 

 inconspicuum Xordst. — C. 

 inflexum Breb.— C, small forms 25'5/* long ; IT, L, VL, Cr ; LG, 29-30// 



broad with processes, 21/* long, a small form, 

 jaculiferum West. — K, D. 



f. biradiata West.— Plankton of LG and of SL. 

 laeve Ealfs var. Clevei Wittr. — D. 



longispinum Bailey. — SL, length 98/*, breadth with spines 117/*. 

 Manfeldtii Delp. — Ac. 

 margaritaeeum (Ehrenb.) Menegh. — C,26-27x 19-20/*, mostly tetraradiate; 



LG. both tri- and tetra-radiate ; W, SL, M, CP ; D, 31 x 21-5-25/*. 

 Meriani Eeinsch. — C, 34 x 25/*, a short form with dilated apices, 

 monticulosum Breb. — C. 

 muticum Breb.— C, W, D ; Cr. 41o x 335/*. 



f. minor Eabenh. — C, 15/* long, 15 - 8/<- broad ; among Utricu/aria 

 minor : in another locality among submerged Hypnum, the 

 average size was 16/* long and 15 - 5/* broad ; D, very small 

 forms in several places, not more than 14'3 x 12'5/*, in 

 another gathering 18x16/*. 

 muricatum Breb. — IT, C ; W, 50 x 37m without spines. 

 O'Mearii Arch. — D, C. 



orbiculare (Ehrenb.) Ealfs, var. hibernicum West) W. & G. S. West — W. 

 var. Ralfsii W. & G. S. West.— IT, L ; W, up to 42 x 33** ; 

 C, 33 x 29/*, another gathering average size 29'5 long, 26'5 

 broad ; D, 30-8 x 27-5/*, and 31 x 27/* ; Cr, 38 X 31/*. 

 var. depressum Eoy & Bissett.— IT, SL, W; D, 28x26-6/*. 

 var. extensum Xordst. — D, 36 - 6x28/*; Cr, 37 - 5x29/t. 



