474 BIDDULPHIA. 



formed of rather coarse beads and intermixed with innumerable abbreviated 

 spines. Girdle face subquadrangular, slightly twisted, at the median portion 

 showing terminal processes very broad, truncate, completely punctate, and the 

 two spines very robust, with apices often bifurcated. Connecting zone with 

 striae formed of puncta, placed in quincunx; somewhat undulated, delicate, 

 about 12 in i c.d.m. Length of valve, 7 to 13 c.d.m. 



Marine. Very rare. Antwerp (Scheldt), Blankenberghe, England (Okeden, Kitton, Stolt., 

 Norman. Comber), Ireland (O'Meara). Found on all the Coasts of the North Sea. 



B. lsevis Ehr. (Ber., 1843, P- 122 > Odontella polymorpha Kiltz. ; 

 H.V.H. Atl., pi. 104, f. 3 and 4*; Type No. 496), plate 20, fig. 639. 



Valve suborbicular or broadly elliptic, bearing near the longitudinal axis 

 two spines opposite, short, obscure, with punctate, radiate striae, somewhat 

 undulate and as it engine-turned, delicate, about 15 or 16 in 1 c.d.m., inter- 

 mixed with abbreviated scattered spines. Girdle face with terminal processes 

 very short, obtuse, truncate, punctate up to the margin. Connecting zone 

 with delicate striae (about 16 in 1 c.d.m.), punctate in quincunx. Length of 

 valve, 5 to 12 c.d.m. 



Marine. Antwerp (Scheldt), England (W. Arnott). 



forma minor. (H.V.H. Atl., pi. 105, f. 4*), plate 20, fig. 640. 

 Smaller, terminal processes scarcely marked. 



B. Smithii (Ralfs) H. Van. Heurck. (Bidduiphia radiata 



Roper ; Ceraiauhts Smithii Ralfs ; Enpodiscus radialus W. Sm., nee Bailey ; 

 H.V.H. Atl., pi. 105, f. 1 and 2* ; Type No. 497), plate 21, fig. 641. 



Valve almost orbicular, sometimes bearing numerous spines, with 

 hexagonal cells, furnished with two marginal processes and two awl- 

 shaped spines rather short, submarginal, forming an angle of 90 with the 

 terminal processes. Girdle face showing in the valve portion the two long 

 terminal processes which are conical, truncate, and entirely punctate, and the 

 two awl-shaped spines not very robust. Connecting zone finely punctate, with 

 puncta in regular lines, about 10 in 1 c.d.m. Frustules free. Length of valve, 

 4 to 12 c.d.m. 



Marine. Very rare. Blankenberghe (2nd Basin), 1878 ; Antwerp (Scheldt), England (W. Sm., 

 Stolt., Norman, W. Arnott !), the Thames (Baxter Coll., No. 2579, 3450). 



