106 THE AMERICAN MONTHLY [Apr 



times larger than either. See frontispiece, fig, 1 for valve 

 view X 284; fig. 1 a, for septum X 284; and fig. 1 b, for 

 zonal view X 284. 



BiDDULPHiA INTERRUPTA. — Valve elliptical, with small 

 rounded processes. Surface convex, finely punctate, the 

 puncta about 10 in .01 mm., radiating in scattered lines 

 from the centre at which are three minute spines. About 

 one-third the distance from centre to processes, at each 

 end, a hyaline band produced by the interruption of 

 puncta, crosses the valve transversely extending nearly to 

 the sides. Valve .112 ram. Campeachy Bay. Rare. Fron- 

 tispiece, fig. 2, X 310. 



BiDDULPHiA VERRUCOSA. — Valve suborbicular, convex 

 Processes very large, cylindrical, truncate. Surface coarse- 

 ly reticulate, the reticulations unequal, irregular, about 2 

 in. 01 mm. Within the reticulations are coarse puncta 

 about 3 in .01 mm. Valve .138 mm. Fosil at Redondo 

 Beach, Cal. Very rare. Frontispiece, fig. 5, X 302. This 

 form, which approaches the Cerataulus group is distin- 

 guished by the incrusted or warty appearance of surface. 



BiDDULPHiA KEELEYi. — Valve broadly rhombic-ellip- 

 tical, rounded at the ends. Surface slightly convex, 

 without depression, reticulated, the reticulations unequal, 

 hexagonal, about 2 in .01 mm., with puncta within the 

 reticulations about 8 in .01 mm. Three stout spines arc 

 placed on each side near the margin. Processes inflated 

 at the base, small at the apex and placed not at the ends 

 of the valve but obliquely opposite, near the ends. Valve 

 .148 mm. U. S. S. "Tuscarora" Soundings, Lat. 36 ° 12' 

 N., Long. 133° 11' W., 1,605 faths. Also coast of Cali- 

 fornia. Rare. Only two specimens have been noticed, one 

 of which was found by Mr. F. J. Keeley on seaweed 

 from California. Frontispiece fig. 4, X 300. 



BiDDULPHiA ARGUS. — Valve broadly elliptical, convex, 

 with an elliptical depression at centre. Surface finely 

 jpticulate^ the reticulations, more or less hexagonal, about 



