352 MEMOIRS OP THE UNIVERSITY OP CALIPORNIA 



The nucleus is ellipsoidal and is situated in the anterior part of the body. Its chromatin 

 contents are arranged in strands following its longer axis. Its major and minor axes are about 

 0.57 and 0.45 transdiameter. 



Near the center of the body is a sphere formed by short rodlets radialty arranged. This 

 probably corresponds to the large spherical masses with radially arranged rodlets such as are 

 figured in Gymnodinium dogieli sp. nov. (pi. 3, fig. 34) and G. radiatum sp. nov. (text fig. Z, 9). 

 In the anterior part of the body is an irregular scarlet-pigment ma.ss, which may probably be 

 the remains of a food body. This has been described by Paulsen (1908) as a stigma. It may 

 be, however, onh' a colored food mass such as may be seen occasionally in other species of the 

 Gramodinioidae, as Gymnodinium aureum (pi. 1, fig. 5), Gyrodinium mclo (pi. 5, 50), and 

 many otliers. 



OccuKEENCE. — Figured by Pouehet (1883, 1885a) from the Atlantic ofi; 

 Concarueau, France, in July. 



Synonymy. — This was originally described by Pouehet (1883, 1885a) as a 

 species of Gymnodinium, and was transferred to Gochlodinium by Lemmer- 

 niann (1899). In the form which Pouehet described in 1883 the girdle makes 

 two turns around the body, both ends terminating on the same face, resulting 

 in an entirel.y different dorsoventral orientation of the body. In his later 

 figure (1885«) the girdle makes 2.5 turns with the ends terminating on opposite 

 faces of the body. This, if valid, would place them in different species, but 

 Pouehet states in his later paper that the figure given therewith is a more correct 

 representation than his earlier figure. 



CoMPAEisoNS. — Only two species in the genus, C. augustum (fig. HH, 15) 

 and C. pulcJicllum. (fig. HH, 16), have a greater torsion of the body than C. 

 orcTdmedcs, the first having a girdle of foiir turns, the second of three turns. 

 It is placed in the C. citron group of the subgenus CocModinium, leading to- 

 wards the subgenus Polydinium. 



Gochlodinium atromaculatum sp. nov. 



Plate 7, figure 71 ; text figures PP ; HH, 6 



Diagnosis. — A large sj^ecies with elongate ellipsoidal body, its length 2.7 

 transdiameters ; girdle a descending left spiral of 2 turns, displaced 1.5 trans- 

 diameters; sulcus with antapical loop, torsion of 1.7 turns; melanin present; 

 color, grey and ochraceous orange. Length, 18-1m. Pacific off La Jolla, Cali- 

 fornia, July. 



Description. — The body is elongate ellipsoidal or asymmetrical subfusiform, obliquely trun- 

 cate anteriorly, tapering posteriorly and circular in cross-section, its length 2.7 transdiameters 

 at the widest part at the middle. The epieone exceeds the hypoeone in size. It is relatively long 

 anterior to the anterior pore with nearly straight sides and obliquely truncate apex. Its length 

 at the proximal and distal ends of the girdle is 0.28 and 0.82 respectively of the total length of 

 the body. Posterior to the proximal junction of the girdle and sulcus it becomes contracted to 

 a slender band which makes one complete turn around the botly, ending in a slender point at the 

 distal junction. The hypoeone sweeps around the body in a broad band from three to six times 

 the width of the posterior part of the epieone, making one complete turn above the distal junction 

 of the girdle and sulcus. Posteriorly it forms a cone of about 65° with rounded antapex. 



