KOFOID : NEW SPECIES OF DINOFLAGELLATES. 201 



Differs from A. quadrisjnna in the more broadly fusiform midbody and in 

 the form of the antapex, having no spheroidal enlargement. 

 Length, 735 fi ; dorso-ventral diameter of midbody, 24 /n. 

 Station, 4740. 



Amphisolenia schroederi, sp. nov, 



Plato 13, Fig. 81. 



A medium-sized species with capitate head, elongated fusiform midbody, and 

 antapex. with two spinules. 



The body is elongated, its length 25 times the dorso-ventral diameter. The 

 head is small, spheroidal, its diameter less than that of the midbody. The 

 neck is about 0.16 of the total length and the midbody is not differentiated. 

 The antapex is not enlarged, is truncate, and deflected to the right. It bears 

 on the angles two stout terminal spines both of which are on the right valve. 



This species differs from A. bispinosa in the location of the terminal spines 

 and in the form of the head. 



Length, 510 /n; dorso-ventral diameter of the midbody, 20 /i. 



Station, 4737. 



TRIPOSOLENIA, Kofoid.i 



Dinophysidae with equal or unequal valves. With three subequal processes 

 from a laterally compressed central midbody, one anterior and two posterior. 

 The anterior process consists of the head, neck, protuberant cytopharyngeal 

 region, and a short process from the midbody. The posterior processes are two 

 symmetrically placed curved antapieal horns, respectively dorsal and ventral 

 in origin, with or without marginal tubercles or terminal spinules. The head 

 and neck resemble those of Amphisolenia. The essential difference between 

 Amphisolenia and Triposolenia lies in the presence in the latter of balanced 

 antapicals arising from a midbody containing the greater mass of protoplasm 

 and the nucleus. In all known forms oi Amphisolenia the midbody is fusiform 

 and bears no dorsal horn, the dorsal horn, if present, arising from the antapieal 

 process. 



The thecal wall is structureless, pitted, or rarely locally reticulate. 



The nucleus is located in the midbody. Chromatophores lacking (?) or of 

 pale greenish-yellow color. 



Sparingly distributed in warm temperate and tropical waters, but rarely 

 taken at the surface. 



Triposolenia longicornis, sp. nov, 



Plate 17, Fig. 101. 



A very large species with long process and long antapieal horns, small tri- 

 angular midbody, and flattened head. 



1 Kofoid, C. A. Dinoflagellata of San Diego Region II. On Triposolenia, a 

 new genus of the Dinophysidae. Univ. of Calif. Pubs. Zool., 3, p. 99-133, plates 

 15-19. 1906. 



