140 MEMOIRS OP THE UNIVERSITY OF CALIFORNIA 



Syxonymy. — This was figured by Claparede and Lachmann as a form of 

 AmphuJinium operculatiim, possibly a different species. Diesing (1866) names 

 it AmphkUuium opcrcnhifiim var. discoidali'i. Its final disposition awaits re- 

 examination of Norwegian material. It appears to be near A. Jierdmani. 



Amphidinium emarginatum Diesing 



Text tigiire V, 21 



Amphidimum operculatiim var. Claparede and Lachmann (1858-61). p. 411, pi 20, fig. 11. 

 A. operculatiim var. emarginata Diesing (1866). p. 98 (384). 



Diagnosis. — A minute species, with broadly ovoidal body, its length 1.1 

 transdiameters ; girdle anterior ; sulcus ( ?) ; colorless. Length, 24m. North Sea 

 on the coast of Norway. 



Description. — The body is broadly ovoidal, widest posteriorly, its length 1.1 transdiameters 

 at the widest part. The dorsal side only is figured b.v Claparede and Lachmann (18.58-61), hence 

 the course of the girdle on the ventral side as well as the sulcus are unknown. The epicone is a 

 minute, caplike portion at the anterior end marked off from the rest of the body by the girdle. 

 It has a length of 0.07 of the total length of the body. The apex is truncate. The hypocone is 

 somewhat spatulate. Its anterior end has a width of 0.36 of the greatest transdiameter of the 

 body. The apex is broad, almost subtruueate. 



The girdle passes transversely across the body at the anterior end, its distance from the apex 

 being 0.07 of tlie total length of the body. A few rounded spherules occupy the middle portions 

 of the body. Nucleus and pusules are not figured. 



Dimensions. — Length, 24^; transdiameter, 21/*. 



Occurrence. — Figured by Claparede and Lachmann (1858-61) from the 

 North Sea off the coast of Norway. 



Synonymy. — This was described by Claparede and Lachmann (1858-61) as 

 Amphidinium operculattiyn variety, possibly a different species. Diesing (1866) 

 describes it as Amphidinium operculatiim var. emarginata (Clap, and Lach.). 

 It is near A. herdmani. Its final disposition awaits re-examination of Nor- 

 wegian material. 



Amphidinium fastigium sp. nov. 



Plate 2, figure IS; text figure U, 11 



DiAGNOSis.^A large species with irregularly ellipsoidal body, its length 1.61 

 transdiameters ; girdle without displacement ; sulcus extending to antapex ; color 

 grey green. Length, 102/*. Pacific off La Jolla, California, June, July. 



Description. — The botly is irregularly ellipsoidal, slightly pointed anteriorly, broadly rounded 

 posteriorly, its length 1.61 transdiameters at the widest part. Its transdiameter and dorso- 

 ventral diameter are subequal. The epicone has the shape of a low, broad cone with the apes 

 more or less flattened and a deep, wide trough extending down the ventral face. Its length on 

 the dorsal and ventral sides is 0.3 and 0.4 of the total length of the body respectively. The 



