KOFOID AND SWEZY: UNARMORED DINOPLAGELLATA 461 



Diagnosis. — A small species with irregularly ellipsoidal body, its length 

 1.3-1.6G transdiameters; girdle a descending left spiral of at least 1.25 tiirns, 

 displaced about 0.5 total length; sulcus with less than 0.5 turn; ocellus with 

 elongated lens and red pigment mass. Length, 44^58/*. Atlantic at Concarneau ; 

 Mediterranean at Cette; April, October. 



Description. — This is based on Pouehet's (1887) and Pavillard's (1905) figures. The body 

 is irregularly ellipsoidal, with protuberant girdle when free, rounded up when encysted ; its 

 length 1.66 (1.3) transdiameters. Tlie epicone and hypoeone are subetiual. Its altitude at the 

 proximal end of the girdle is about 0.33 of the total length and over 0.66 at the distal end. The 

 apex is broadly rounded. The antapex of the hypoeone is broadly rounded in the cyst, asym- 

 metrical and longer on its left side in the free state. In the lower one of Pouehet's (1887) two 

 figures the postmargin is obliquely truncate and the body lacks the food ball present in the 

 upper figure. Pouchet states, however, that they represent two individuals. A similar truncate 

 appearance follows the extrusion of food balls at the antapex in other species. 



The girdle appears to make about 1.5 turns in Pouehet's figures, but is not completely 

 portraj'ed in Pavillard's. Its displacement is at least 0.5 the length of the body. The furrow is 

 deeply impressed with protuberant lips in the free state. 



The sulcus extends ( ?) a short distance on the epicone, and continues as a narrow groove in 

 a spiral course of 0.25 to 0.50 turn to the po.stmargin. 



The ocellus is of the concentrated or simple, more integrated type. It lies at the left of the 

 posterior part of the intercingular sulcus with its axis directed anterodextrally at about 50° 

 from the horizontal. Its length is 0.40 to 0.45 trausdiameter. It consists of an elongated lens 

 imbedded at one end in a flattened hemispherical bright red pigment mass. In Pouehet's figure 

 the pigment is light rose, in Pavillard's scarlet with darker margin. In the former the lens is 

 swollen distally and its exposed length equals the diameter of the pigment mass. It shows no 

 lamellae. In Pavillard's figure it is 0.65 of the diameter of the pigment mass in length, not 

 swollen distally, and has several transverse lamellae. 



The nucleus lies anteriorly in the epicone, is ellipsoidal in form with its major and minor 

 axes 0.75 and 0.50 trausdiameter in length respectively and oblique to the axis of the body. It 

 contains fine parallel chromatin threads. An orchraceous food ball or a vesicle filled with a 

 fluid colored by diatomin is figured by both Pouchet and Pavillard. The former states that the 

 plasma is completely hyaline with a yellowish tint locally. It is not rosy as figured by Schiitt 

 (1895) in the forms he refers to this species. 



Dimensions. — Length, 44 (58)^; trausdiameter, 25 (46)/*; diameter of 

 nucleus, 17 (34)/" ; length of ocellus, 10 (22)/*. Pouchet states that the length of 

 the body is 30m; but the figure measures 44/* on the basis of the stated magnifi- 

 cation, 500 diameters. The dimensions in brackets are of Pavillard's figure. 



Occurrence.- — Two individuals with red pigment mass were taken in a 

 haul of a No. 12 silk net from 120 meters to the surface on July 7, 1904, about 

 10 miles southwest of Point Loma, California, in surface temperatures of 

 approximately 17°-18° C. Their lengths were 45m and 50m and transdiameters 

 24m and 30m respectively. 



Originally described by Pouchet (1887) fi-om the plankton of the Atlantic 

 at Concarneau, France, where he discovered it on March 25, and at a later visit 

 on April 23 to 26. The only other record which can be assigned critically to 

 this species is that of Pavillard (1905), whose figure bears a marked similarity 

 to Pouehet's original sketches and has the red pigineut mass as originally 



