DINOFLAGELLATA 227 



Family 6 Blastodiniidae Kofoid et Swezy 



All parasitic in or on plants and animals; in colony forming 

 genera, there occur trophoc5rte (Chatton) by which organism is 

 attached to host and more or less numerous gonocytes (Chatton). 



Genus Blastodinium Chatton. In gut of copepods; spindle- 

 shaped, arched, ends attenuate)!; envelope (not cellulose) often 

 with 2 spiral rows of bristles; young forms binucleate; when pres- 

 ent, chromatophores in yellowdsh brown network; swarmers sim- 

 ilar to those of Gymnodinium; in salt water. Many species. 



B. spinulosum C. (Fig. 103, a). About 235^ by 33-39/^; swarm- 

 ers 5-lOyu; in Palacalanus parvus, Clausocalanus arcuicornis and 

 C. furcatus. 



Genus Oodinium Chatton. Spherical or pyriform ; with a short 

 stalk; nucleus large; often with yellowish pigment; on Salpa, An- 

 nelida, Siphonophora, etc. 



0. poucheti (Lemmermann) (Fig. 103, 6, c). Fully grown indi- 

 viduals up to 170 fji long; bright yellow ochre; mature forms be- 

 come detached and float, dividing into numerous gymnodinium- 

 like swarmers; on the tunicate, Oikopleura dioica. 



Genus Apodinium Chatton. Young individuals elongate, spher- 

 ical or pyriform; binucleate; adult colorless; formation of numer- 

 ous swarmers in adult stage is peculiar in that lower of the 2 

 individuals formed at each division secretes a new envelope, and 

 delays its further division until the upper divides for the second 

 time, leaving several open cups; on tunicates. 



A. mycetoides C. (Fig. 103, d, e). On gill-slits of Fritillaria pel- 

 lucida. 



Genus Chytriodinium Chatton. In eggs of planktonic copepods; 

 young individuals grow at the expense of host egg and when fully 

 formed, body divides into many parts, each producing 4 swarm- 

 ers. Several species. 



C. parasiticum (Dogiel) (Fig. 103,/). In copepod eggs; Naples. 

 Genus Trypanodinium Chatton. In copepod eggs; swarmer- 



stage only known. 



T. ovicola C. (Fig. 103, g). Swarmers biflagellate ; about 15)u 

 long. 



Genus Duboscquella Chatton. Rounded cell with a large nu- 

 cleus; parasitic in Tintinnidiidae. One species. 



D. tintinnicola (Lohmann) (Fig. 103, h). Intracellular stage 

 oval, about lOO^t in diameter with a large nucleus; swarmers bi- 

 flagellate. 



