36 BULLETIN 100, UNITED STATES NATIONAL MUSEUM 



BIDDULPHIA CONSIMILIS (Grunow) Boyer 



(Van Huerck, Synopsis, pi. 108, fig. 2; Schmidt, Atlas, pi. 84, figs. 13-14, and 

 pi. 84, fig. 17, misnamed.) 



The only locality hitherto reported for this species is the fossil 

 deposit at Santa Monica, Calif. The finding therefore of several 

 unmistakable specimens in Philippine Islands dredgings is interesting. 



BIDDULPHIA CORNIGERA, new species 



Plate 8, fig. 2 



Valve seen in face view broadly elliptical with pointed ends forming 

 an obtuse angle, in which, close to the apices, arise two long horns; 

 a circular or slighty oval central area represents about four-fifths to 

 five-sixths of the surface of the valve and is slightly elevated above 

 the part surrounding it, the line of separation being armed with an 

 indefinite number of stout spines irregularly placed, sometimes grouped 

 on one side, generally scattered along opposite sides ; the rest of the 

 valve thickly covered with short prickles ; in side (or girdle) view the 

 two long horns are seen to be divergent and to have enlarged bulbous 

 ends, slightly pointed on the inner side; the rim (joining the girdle) 

 is broad, hyaline, and extends beyond the sides of the valve ; the 

 girdle is covered with a fine rugose marking. 



Length of valve, 0.046-0.124; width; 0.028-0.106 height of frustule; 

 0.073-0.096 mm. 



The question of the identity of this species and B. expedita Janisch 

 is an interesting but unsolvable one. Certain small specimens with 

 wide girdles appear, if viewed obliquely, exactly like the sketchy fig- 

 ure of B. expedita given in his Diatoms of the Gazelle Expedition, 

 plate 21, figure 7, and reproduced in Schmidt's Atlas plate 121 figure 

 3. But with no description, no direct side (girdle) view, and no 

 knowledge of the shape and markings of the valves it is idle to attempt 

 any conclusion. All diatomists know that two species of Biddulphia 

 may closely resemble each other in one view and yet show marked 

 distinctions in the other view. In fact certain frustules of the widely 

 different diatom, B. cingulata, when slightly turned and seen in the 

 girdle view, are equally like the crude figure of B. expedita. 



It is most desirable, whenever possible, to have both the face and 

 side views of the Biddulphiae. I am compelled to ignore the B. ex- 

 pedita of Jansich as indeterminate. This species is abundant in many 

 of the Philippine dredgings. In valve view it somewhat resembles 

 the fossil B. oamaruensis Grove and Sturt (Oamaru, Diat., p. 5, pi. 

 l,fig. 10). 



Type— Cat. No. 43589, U.S.N. M. 



