308 Proceedings of the Royal Irish Academy. 
been adopted by Kiitzing for the reception of a single species which 
was named by him Doryphoraamphiceros. His definition of the genus 
was, ‘‘frustules simple, depressed on the secondary side, punctate, 
elliptico-lanceolate, stipitate.”” Bac. p. 74. Influenced, no doubt, by 
the consideration of the last named characteristic, Wm. Smith adopted 
the genus as the proper place for another form named by him Dory- 
phora Boeckii, and to some extent amended the definition: ‘‘ Frustules 
stipitate, lanceolate, or elliptical; valve with a median line; nodules 
obsolete.” —B. D., Vol. i., p. 77. This definition is not quite correct 
as respects either of the species included under this generic designa- 
tion, for Doryphora amphiceros has no median line, properly so called ; 
and the nodules, though small, are not obsolete inthe case of Dory- 
phora Boeckii. The latter species, Ralfs, as Ehrenberg had done before, 
refers to the genus Cocconema, but properly remarks, ‘‘ This species is, 
no doubt, wrongly referred to Cocconema, since both margins of the 
lateral valves are symmetrical. We regard it asa stalked Navicula; 
and find a central, though inconspicuous nodule, a fact which forbids it 
being placed in Doryphora, as Professor Smith proposed.’’—In Pritch., 
p- 878. Grunow transfers Doryphora amphiceros to his new genus 
Rhaphoneis, and recognising the intimate relationship of Doryphora 
Boeckii to Nayicula, suggested the adoption of a new generic designa- 
tion, Brebissonia. defining it simply as a stipitate Navicula. 
Heiberg recognises the proper relationship of the species, as Ralfs 
and Grunow had done, but rejecting the stipitate character as of no con- 
sequence, described the formas Navicula Boecku.—De Danske Diat., 
p. 85. At all events, it is better to drop the genus Doryphora, which has 
been so ill defined, lest confusion should arise from maintaining it, 
even though witha more precise definition ; and, as I think that the 
stipitate mode of growth should not be regarded as of no importance, 
I adopt the suggestion of Grunow above referred to. 
Brebissonia boeckii, Ehr. Marine. 
Valve on side view lanceolate. Striz costate, close, radiate, median 
line obvious, with large end nodules, and ending towards the central 
nodule, in pin-head-like expansions; central nodule long and narrow, 
with a narrow free space at each side of the median line. (PI. 29, 
fig, 22. 
a ae Verhand. der K.K., Zool. Bot. Gesel., Band x., 1860, 
p. 512.—Cocconema boeckii, Ehr. Infus., T. xix., fig. 5. Kitz. Bac., 
p. 817-1: vi, fig. 5.) Ralis; an Pritch.jpo 878, Bl sapere: 462 sab: 
Fl. Eur., sect. i., p. 83.—Doryphora boecku, Wm. Sm., B. D., Vol. 
1., p. 77, Pl. xxiy., fig. 223.—Navicula boeckiu, Heiberg, De Danske 
Diat., p. 85. 
Stomachs of Ascidians, Roundstone Bay, Co. Galway. Salt ditch on 
banks of Slaney, near Wexford. River Slaney, Killurin, Co. Wex- 
ford. 
