ill!Ill

BIDDULPHIA. 473
B. Baileyii W. Sm. (S.B.D., ii., p. 50, pi. 62, f. 322 ; Zygoceros
mobilicnsis Bail. ; H.V.H. Atl., pi. 10 1, f. 4-6*), plate 20, fig. 636.
A delicate, very imperfectly silicious diatom. Valve broadly lanceolate,
bearing two spines alternating with the terminal processes, and situated at the
lower and upper third near the longitudinal axis of the valve ; puncta in
quincunx very delicate, about 12 to 14 striae in 1 c.d.m. Girdle face showing
the valve portion with centre flat or concave, the conical terminal processes
completely punctate, with truncate, somewhat capitate, ends, they and the spines
very long, somewhat bifurcated at the apex, each being
borne on a small
elevation of the valve. Connecting membrane with puncta in quincunx,
excessively delicate, about 18 striae in 1 c.d.m. Length of valve, 7
c.d.m.
to 16
Marine. Blankenberghe (H.V.H.), England (W. Sm., Williamson, Kitton, Stolt., Norman,
Comber), Ireland (O'Meara),
B. granulata Roper (T.M.S., 1859, vii., p. 13, pi. 1, f. io-u, pi.
ii., f. 12 ; H.V.H. All., pi. 99, f. 7 and 8, and pi. 101, f. 4*. In the latter figure
the general outline is very exact, but in the fair copy of the drawing the small
spines on the valve have been accidentally omitted; Type No. 492), plate
20, fig. 637.
Valve ellipticdanceolate, bearing two very long spines alternate with the
terminal processes, approximate to them and to the longitudinal axis of the
valve ; striated in quincunx (about 13 or 14 in i c.d.m.), and bearing numerous
small awl-shaped spines, about 4 in 1 c.d.m., placed in irregular lines. Girdle
face quadrangular, showing the valve portion with the centre fiat or concave,
the processes inflated, then abruptly attenuate on the external side, punctate
up to the apex, which is somewhat rounded, and the spines very long, often
flexed at an obtuse angle near their middle. Connecting zone with puncta
in quincunx, with 14 stria? in 1 c.d.m. Length of valve, 5
(in the specimens observed).
to 8 c.d.m.
Marine. Very rare. Antwerp (Scheldt), Blankenberghe, England (Coll. W. Arnott !, Comber,
Stolt., Norman).
B. turgida W. Sm. (S.B.D., ii., p. 50, pi. 62, f. 38; Cerataulus
turgida Ehr.; H.V.H. Atl., pi. 104, f. 1 and 2* ; Type No. 495), plate 21,
fig. 638.
Valve varying from a round to a longly elliptic form ;
sometimes furnished
near the margin with a circlet of very short spines, bearing diagonally two
broad truncate processes and two stout spines ; striae undulate, 9 in 1 c.d.m.,