O’Mrara—eport on the Irish Diatomacee. 335 
at the ends. Striz fine, obscurely punctate, convergent about the 
central nodule, and for a considerable distance from it, towards the 
ends straight and radiate. 
Agardh. Conspect., p. 20. Grev. Brit. Flora, p.412. Harvey’s 
Manual, p. 210. Kitz. Bac., p. 114, T. xxvu., fig. 6. Wm. Sm., 
B. D., Vol.ii., p. 74, Pl. lvi., fig. 355. Rab. Fl. Eur., sect. 1, p. 268.— 
Micromega helmintosum, Ralfs, in Pritch., p. 830. 
- Howth, Malahide, Co. Dublin. Carnlough Bay, collected by Dr. 
David Moore. 
Schizonema comoides, (Agardh.) Marine. 
‘‘Frond filiform, simple below, much divided and fasciculated 
above. Frustulescrowded.”—Wnm. Smith. Frustulessmall, length about 
‘0010, somewhat rhombic on front view, rounded slightly at the ends. 
Striz strong and distant at centre, finer and closer towards the end ; 
on front view linear, in outline rounded at ends. 
Agardh. Conspect., p. 19. Harvey’s Manual, p. 2138. Wm. Sm., 
B. D., Vol. u., p. 75, Pl. lvu., fig. 358. Rab. Fl. Eur., sect. 1., p. 
268.—Schizonema araneosum, Kutz. Bac., p. 1138, T. xxiv., fig. 2, T. 
xxy., fig. ix.— Micromega comoides, Ralfs, in Pritch., p. 934. 
Carnlough Bay, Co. Antrim, collected by Dr. David Moore. Howth, 
Malahide, Co. Dublin. 
Schizonema parasiticum, (Harvey.) Marine. 
‘‘Frond capillary, branched, filaments slightly cohering above. 
Ramuli short, patent. Mucus oftenrugose. Frustules crowded in files, 
more or less distant. Valves elliptico-lanceolate, acute. Length of frond 
5” ; length of frustule :0011; breadth of valve -0002.”—Wm. Smith. 
Strie extremely fine. Frustule on front view quadrangular. 
Harvey’s Manual, p. 213. Wm. Sm. B. D., Vol. 11., p. 79, Pl. lix., 
fig. 37. Rab. Fl. Eur., p. 273.—Micromega parasiticum, Kitz: Bac., 
p. 116, 7. xxvu., fe. 2.” Ralfs, in Pritch., p_/932. 
Malahide, Salt Hill, Co. Dublin. 
Schizonema laciniatum, (Harvey.) Marine. 
“Frond filiform, much branched, filaments often adhering into 
rope-like tufts. Ramuliverylong. Frustules numerous, crowded in irre- 
gular files. Valves elliptical, somewhat acute. Length of frustule:0018; 
breadth of valve :00035.”—Wm. Smith. Valves striate; strize punctate, 
gently radiate. On front view frustules broader at middle than at 
ends, ends rounded off; side view coming largely into sight when 
observed in front, the inner margins nearly meeting the connecting 
membrane, and at the ends receding therefrom. 
On careful inspection of authentic specimens of Schizonema impli- 
catum (Harvey), I find the frustules on side and front view so like one 
