338 Proceedings of the Royal Irish Academy. 



been adopted by Kiitzing for the reception of a single species wbich 

 was named by him Doryphora amphiceros. 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 DoryiDhora amphiceros has no median line, properly so called ; 

 and the nodules, though small, are not obsolete in the 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. AVe regard it as a 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 

 Bhaphoneis, and recognising the intimate relationship of Doryphora 

 Boeckii to ITavicula, 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 Balfs 

 and Grunow had done, but rejecting the stipitate character as of no con- 

 sequence, described the form as Navicula Boeckii. — 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 with a 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. 



JBrelissonia boeckii, Ehr. Marine. 



Yalve on side view lanceolate. Striae 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.) 



Grunow, Verhand. der X. K., Zool. Bot. Gesel., Band x., 1860, 

 p. 512. — Cocconema boeckii, Ehr. Infus., T. xix., fig. 5. Kiitz. Bac, 

 p. 81, T. vi., fig. 5. Balfs, in Pritch., p. 878, PI. vii., fig. 48. Bab. 

 El. Eur., sect, i., p. 83. — Doryphora boeckii, Wm. Sm., B. D., Vol. 

 i., p. 77, PI. xxiv., fig. 223. — jN'avicula boeckii, Heiberg, De Danske 

 Diat., p. 85. 



Stomachs of Ascidians, Roundstone Bay, Co. Galway. Salt ditch on 

 banks of Shm.ey, near Wexford. Biver Slanev, Killurin, Co. Wex- 

 ford. ' ^ 



