O'Meara — Bejjorf on the Irish Diatomacece. 275 



Biddulphia laileyii, (Wm. Sm.) Marine. 



Frustules, on front view, receding at the sides in a gentle slope ; end 

 surfaces nearly flat, ■with two slight elevations on which the spines are 

 situated ; processes long, and. narrow towards the extremity, slightly 

 curving inwards ; striation very obscure ; punctate ; puncta parallel. 

 On side view valves broadly elliptical ; processes at extremities of the 

 longitudinal axis ; spines two, situated a little to the right and left 

 of same, about one-third of the entire length from extremities ; striae 

 very fine ; lines of puncta appearing to cross each other, except upon 

 a vacant, sigmoid, narrow space in the middle. (PI. 27, fig. 8.) 



Wm. Sm., B. D., Yol. ii., p. 50, Pis. xlv. and Ixii., fig. 322. Eab. 

 Fl. Eur., sect. 1, p. 311. Eoper, Q. J.M. S., Oct., 1858, p. 12, 

 PI. i., figs. 5-9. — Zygoceros mobiliensis, EaLfs, in Pritch, p. 850,. 

 PL vi., fig. 11. 



Salt ditch near "Wexford. Tacumshane, Co. Wexford. Dundalk^ 

 Co. Louth. Salt marsh, Drehidnamaud, Co. Kerry. 



(b.) Surfaces of the valves undulate. 



Biddulphia pulchella, (Gray.) Marine. 



On front view the sides incline inwards towards the processes ; the 

 valves divided into compartments, from three to seven in number, the 

 central being the largest and most elevated, from which, in perfect 

 specimens, two or three spines are projected ; compartments separated 

 by what appear strong costae ; processes short, rounded at extremities ; 

 striation areolate ; areoles roundish, and nearly parallel ; connecting 

 zone striate. On side view the valve is broadly elliptical ; areolea 

 ranged round the central point. (PL 27, fig. 9.) 



Wm. Sm., B. D., VoL iL, p. 48, Pis. xliv., xlv., xlvL, fig. 321. 

 Eoper, Q. J. M. S., Oct., 1858, p. 7. Ealfs, in Pritch, p. 848, PL ii., 

 figs. 46-50. — Biddulphia trilocularis ; B. quinquelocularis ; B. septem- 

 locularis, Kiitz. Bac, p. 138, T. xxix., fig. 89, T. xix., fig. 1, T. xix., 

 fig. 2. — Diatoma Biddulphianum, Agardh, Syst.Alg., p. 5. — Denticella 

 Biddulphia, Ehr., Berl. Trans., 1843. 



Malahide, Ireland's Eye, Baldoyle, Co. Dublin. Sea-weeds, 

 Giants' Causeway, Co. Antrim. Stomachs of Ascidians, Eoundstone 

 Bay, Arran Islands, Co. Galway. 



Familt III. TEICEEATIE^. 



Valves on side view presenting three or more angles, with a pro- 

 cess springing from each angle. 



This group includes the genera Amphitetras, Triceratium and Trina- 

 cria, which, in consequence of their obvious resemblance, are placed 



