O’Mrara—Report on the Irish Diatomacee. 401 
there, but with precise focusing they disappear, or, if they appear at 
all, are very faint. Schmidt’s figure represents the species as more 
robust than mine, but the compartments on either side of the median 
one are just as in mine. 
Arran Islands; Stomachs of Ascidians, Broadhaven Bay, Co. Gal- 
way. 
Navieula bombus, (Ehr.) Marine. 
Valves much constricted, lobes much inflated ; median compart- 
ment very wide, the boundary lines strong, and having the edges 
milled, greatly curved at the ends, slightly constricted in the middle ; 
compartments at either side narrow; scarcely striate, or if striate, the 
strive very faint; marginal band of strive very wide; strive remote, dis- 
tinctly moniliform, the beads being distant, parallel in the middle, 
more and more radiate towards the ends; length ‘00386, breadth 
0016; breadth at the constriction ‘0010. (Plate 33, fig. 28.) 
Ralfs, in Pritch., p. 893, who attributes the species to Ehrenberg. 
Gregory, Diat. of Clyde, p. 484, Pl. ix., fig. 12. Rab. Fl. Eur. Ale., 
pect, p 204. “Donkin. N. He: Brit: “Diat:; p. 50): Pl. «vi. fig: Ta. 
This figure fairly represents the characters of the species, but in my 
specimens the constriction is deeper, and the compartments at either 
side of the median one are much narrower. Cleve, Om Svenska och 
Norska Diat., p. 226. 
Arran Islands; Stomachs of Ascidians, Broadhayen Bay; Sto- 
machs of Ascidians, Roundstone Bay, Co. Galway. Ballysodare, Co. 
Sligo. Malahide; Portmarnock, Co. Dublin. Bannow, Co. Wex- 
ford. Stomachs of Ascidians, coast of Co. Clare. Stomachs of Ascidians, 
Belfast Lough, Co. Antrim. 
Navicula entomon, (Ehr.) Marine. 
Valves not so deeply constricted as in Navicula bombus; median 
compartment narrow, inflexed at the ends, slightly constricted in the 
middle; compartments at either side narrow, unstriate, or strie very 
obscure; marginal band of striae broad; striz distinctly moniliform, 
distant, parallel in the middle, radiate towards the ends; length 
"0030, breadth 0012; breadth at the constriction °0010. 
This species strongly resembles Navicula bombus in the character 
of the moniliform strie ; the constriction is, however, not so deep, nor 
are the lobes so much expanded; the median compartment also is 
much narrower in this species than it is in the other. 
Kiitz. Bac., p. 100, T. xxviii., fig. 74. In this case, the figure is 
very obscure. Kiitzing attributes the species to Ehrenberg. Ralis, in 
Pritch., p. 893. Donkin, N. H. Brit. Diat., p. 49, Pl. vu., fig. 5. 
This figure represents the species as much larger, and the compart- 
