O’Mrara—Report on the Irish Diatomacee. 331 
or a new genus established to receive it.’”’—Schizonema eximium, 
Thwaites, Ann. Nat. Hist., March, 1848. Rab. Fl. Eur., sect. 1, 
p- 266.—Gloionema sigmoides, Ehr. Abh., 1845, p. 78.—Encyonema 
sigmoides, Kiitz. Alg., p. 62.—Endosigma eximium, De Bréb. 
Tacumshane, Co. Wexford. Near Railway station, Newtown- 
limavady, Co. Derry. 
Colletonema vulgare, (Thwaites). Fresh water. 
Frond occasionally divided; frustules elliptical, lanceolate, strice 
very fine. 
In Smith’s figure the strie are described as radiate, but I have 
never been able to resolve them. 
Wantvome, Bid.) “Vol. 1.,,p. 70, .Plo ly, fig. 351. »Grunow,; 
Verhand. der K. K. Zool. Bot. Gesel., Band x., 1860, p. 572. Ralfs, 
in Pritch., p. 926.—Schizonema vulgare, Thwaites, Ann. Nat., Hist., 
2nd jeemiess, Vel. 1-5) p., 10} Pl. x1.,. fig: H.. Rab. FL. Eur:, sect: 1, 
p. 265,—Navicula vulgaris, Heiberg, De Danske Diat., p. 83. 
Carrickmacreilly Mountain near Glanealy, Wicklow: the spezies is 
very uncommon. 
Colletonema neglectum, (Thwaites.) Fresh water. 
Frond slightly divided; frustules closely packed; elliptical, lan- 
ceolate ; extremities obtuse; strie finely costate, radiate. (Pl. 29, 
fig. 15. 
— Sm., B: D.; .Vol.i., p. 70, Pl. lvi.; fig. 352. . Ralfs, in Pritch., 
p. 926. Grunow, Verhand. der K. K. Zool. Bot. Gesel., Band x., 
p. 571.—Schizonema neglectum, Thwaites, Ann. Nat. Hist., 2nd 
Series, Vol..i. p. 21,,Pl. xu., J. Rab. Fl. Eur., sect. 1, p. 265. 
Genus lV. Brrxetzya, Greville. 
Frond branched, the branches springing from a basal tubercle. 
Most authors adopt this genus, but Heiberg rejects it as unneces- 
sary, and includes the species under Navicula. 
Berkeleya fragilis, (Greville.) Marine. 
Frustules closely packed in the tubes. Valves elliptical, lanceo- 
late, broadly rounded at the ends. Striz obscure. (PI. 29, fig. 16.) 
Grev. Scot. Crypt. Flora. tab. 294. Do. Brit. Flora, p.416. Ralfs, 
Ann. Nat. Hist., 1st Series, Vol. xvi., Pl. i., fig. 2. Do., in Pritch., 
pe926« Kutz Bae:,ip? 109.) Wm. Sm., B.D; Vol:)it., p..67,, Pl., liv., 
fig. 844. Grunow, Verhand. der K. K. Zool. Bot. Gesel., Band x., 
1860, p. 512. Rab. Fl. Eur., sect. 1, p. 264.—Navicula fragilis, Hei- 
berg, De Danske Diat., p.84. Bangia micans, Lyngbye, Tent. Hydro- 
R.1. A. PROC., SER. II., VOL. II., 8CIENCE. pe 
