48 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



of feeding, has ingested a dinoflagellate which still shows its characteristic 

 girdle. 



In the species containing an abundance of yellow ochraceous pigment, as 

 in G. ochraceum and G. fulvinu, as well as those with red pigment, as G. coral- 

 linum, G. virgatuni, and G. hritannio, the cytoplasm is usually clear, with few 

 inclusions, and gives no e^ddences of the formation of starch granules or re- 

 lated products. Food bodies may be occasionally found in G. coralUnum as 

 well as in G. ochraceum, though most of the specimens of these species noted 

 present no clue to their manner of feeding. In G. virgatum (pi. 10, fig. 112) 

 the posterior end of the body is distorted, presenting the same appearance found 

 in Gi/mnodinium keterostriatum after the ejection of a food mass. 



In another species, G. maculatum (pi. 6, fig. 62), also plentifully supplied 

 with pigment of a A'iolet color, food bodies were occasionally found within the 

 cytoplasm, which, at other times, was remarkably clear and free from cell inclu- 

 sions of all kinds. It is probable, therefore, that these f onus have a saprophytic 

 or holozoic mode of food-getting. The numbers of individuals of some of 

 these species that were observed, however, were too small to be conclusive on 

 this point. 



We find in the members of the genus Coclilodinium evidences of holozoic 

 nutrition sunilar to those observed in the three preceding genera. One of the 

 most striking instances of this is that seen in Cochlodinium rosaccum (pi. 8, 

 fig. 85) with its ingested Pouchctia. This is one of many instances in which 

 members of the latter genus have been devoured by other dinoflagellates, and 

 might suggest its desirability as a choice article of food. It is, however, 

 probably no more frequently captured than are the membei'S of the other genera, 

 but the latter quickly lose their characteristic features and become indistin- 

 guishable in a food vacuole. AMth Ponchetia. on the contrary, the ocellus re- 

 tains its characteristic appearance until final disintegration of the body, making 

 it easy to identify the generic, though not the specific, status of the digesting 

 food mass. 



In the species CochJodiniion vinctum (pi. 2, fig. 15), of which a number of 

 individuals were examined, it was found that a large food body of similar 

 appearance was present in each specimen examined. This was located in the 

 anterodextral part of the body. It is a reniform, greenish or oil yellow, vacuo- 

 lated body with its surface covered with small, highly refractive spherules re- 

 sembling oil drops. These are arranged over the surface with considerable 

 regularity. Its center contains an elongated pinkish vacuole and in one instance 

 what appears to be a nucleus of the dinoflagellate t\"pe. Other bodies were 

 sometimes present in the cytoplasm. 



In Ncmafodiuiiim pnrfifum (pi. 6, fig. 68) a species of G//»nwdi)iiiim is 

 shown, with its girdle still intact. Other members of this genus also present 

 evidences of food masses within the plasma. 



In Pouchetia we find the most strildng instance presented in the group 

 thus far. One specimen of P. voracis was found with the theca of a Peridinimn 



