170 MEMOIRS OF THE UNIVERSITY OF CALIFORNIA 



HisTOEif'AL Discussion 



This gemis ^as established by Stein (1878) for t^Yo species described by 

 Ehrenberg (1834, 1838) as Pcridiuiuni fiiscum and P. jjuhnscidus. He con- 

 sidered this the basic tjqae for the more comj^lex Peridiniidae. Later (1883) 

 he changed Gymnodinium pulviscidus (Ehr.) to GJenodinium, pidviscidus. He 

 also (1883) described Gi/wnodiuium acrufjinosiun and G. vorticella and trans- 

 ferred to the genus Schmarda's Glenodiuiian roscolmn as Gipnnodininm 

 roscolnm. His use of the species designation G. pidrisndiis has proved a source 

 of some confusion in later literature. Klebs (1883) records, without figuring, 

 a form from fresh water as G. pidviscidtis with a note that he is not certain of 

 its identity with Stein's species, overlooking the fact that Stein had changed 

 that species to GJcnodiniiuii. Pouchet (1885^) later gives the name G. pidvis- 

 cidns to a Gymnodinkim-like organism parasitic on Appcndicidaria. Lemmer- 

 mann (1899) reserves the name G. piiJ viscid us for Kleb's form and gives to 

 Pouchet 's parasitic organism the name 6^. poucJieti. Chatton (1906) notices the 

 close relation of Pouchet 's species with his newly created genus Blastodinium, 

 changing its name to Oodiuium poucJietl. As a parasitic genus with a compli- 

 cated life cycle it does not belong with Gyrnnodinkmi as that genus is at present 

 constituted, and we therefore reject it, placing it with the Blastodiniidae. With 

 it and for the same reason we reject G. parasificiim. parasitic on co^jepods, and 

 G. aftinis from Gi/mnodhiinm. 



Protozoologists following Stein placed in this genus forms representing 

 Gymnodinium, Gyrodinium, Cocldndinium, and Pouchetia as here constituted. 

 Bergh (1881?j) added to the genus G. gracile and also G. s pi rale, later changed 

 by Schiitt (1896) to Spirodinium spinde and by us to Gyrodinium spiraJe. The 

 same year Penard (1881) descril)ed G. Jiclveficum, G. miraljde, G. mirahile var. 

 rufescens, changed by Lemmermann (1900) to G. rufescens and G. viride 

 (=^G. iiherrinum Alhnan). Saville-Kent (1880-82) added G. mariuu))! and 

 Danysz (1886), G. musei. Pouchet described the following species, to which 

 we add our present allocation of them : 



Gymnodinium archimedes, (1883) ^^C odd odinium archimcdes Lemmermann (1899). 



G. spirale var. striatum, (1883) ^Gyrodinium fissum Kofoid and Swezj^ 



G. spirale var. cornutum, f 1885a) = Spirodinium cornutum (Pouchet) Lemmermann 



(1899) =Cochlodinium cornutum (Pouchet) Kofoid and Swezy. 

 G. teredo (188oa) ^Torodinium teredo (Kofoid and Swezy). 

 G. cra^ssum, {1885b) ^ Spirodinium crassum (Ponchet) Lemmermann (1899) =Gyro- 



diniurn crassum, Kofoid and Swezj-. 

 G. polyphemus, (ISSob) = PoucJietia polyphcmus (Pouchet) Kofoid and Swezy. 

 G. helix (1887) =Cochlodinium helix (Pouchet) Lemmermann (1899). 

 G. pulypliemus \av. ixigrum, (1887) = Pouchetia nigra (Pouchet) Lemmermann; (1899) 



^=Protopsis nigra (Poucliet) Kofoid and Swezy. 

 G. pulvisculus=G. poucheti, Lemmermann (1899) = Oodinium poucheti (Lemmermann) 



Chatton (1912). 



