O'Meaea — Report on the Irish Biatomacece. 289 



Dimeregramma nanum, (Greg.) Marine. 



Frustules on front view slightly arched, short, but broad ; end of 

 striae appearing at the margin ; on side view broadly elliptical, lanceo- 

 late ; marginal strise long, leaving biit a narrow unstriated median, 

 space. 



Ealfs, in Pritch., p. 790, Plate iv., fig. 33. — Dimeregramma 

 Gregoriannm, Grunow, Yerhand der K. K. Zool. Bot. Gesel., Band 

 xii., 1862, p. 346. This last named author changes the specific 

 name given by the discoverer, on the ground that the original designa- 

 tion answers only for the smaller forms, the species varying greatly as 

 regards size. Rabenhorst retains the original specific name imposed 

 by Gregory, and adopts the generic name Dimeregramma, but eiTO- 

 neously ascribes the species to Pritchard. PL Eux., sect. 1, p. 123. — 

 Denticula nana, Gregory, Diat. of the Clyde, p. 23, PI. x., fig. 34. 



Stomachs of Ascidians, BeKast Lough, Co. Antrim. 



Dimeregramma minus, (Greg.) Marine. 



Prustules on front view as in the preceding species, only narrower 

 for the length ; on side view narrow, elliptical, and pointed at the 

 ends; marginal strise long, leaving the central unstriate band very 

 narrow. 



EaKs, in Pritch., p. 790. Grunow, Yerhand der K. K. Zool. Bot., 

 Gesel., Band xii., 1862, p. 376, T. iv., fig. 29. Eab. PI. Eur., sect. 

 1, p. 123, who attributes this species as well as the preceding to 

 Pritchard. — Denticula minor, Gregory, Diat. of Clyde, p. 23, PL x., 

 fig. 35. 



On piles of wooden bridge, DoUymount. On sea- weeds, Ireland's 

 Eye, Co. Dublin. 



Dimeregramma distans, (Greg.) Marine. 



Prustules on front view similar in outline to the preceding species ; 

 on side view broadly elliptical, and somewhat lanceolate at the ends ; 

 marginal striae costate, "short, leaving a broad, unstriate, median space. 

 (PL 27, fig. 19.) 



Ealfs, in Pritch., p. 790, PL iv., fig. 34. Grunow, Yerhand der 

 K.K Zool. Bot. Gesel., Band xii., 1862, p. 376. Eab. PL Eur., 

 sect. 1, p. 123. — Denticula distans, Gregory, Diat. of Clyde, p. 23, PL 

 X., fig. 36. 



Stomachs of Ascidians, Belfast Lough, Co. Antrim. 



Dimeregramma marinum, (Greg.) Marine. 



Prustules on front view linear, slightly constricted at the ends ; on 

 side view linear, with cuneate ends, and slightly expanded in the 

 middle ; striae monilif orm, long, leaving the median unstriate band 



