31] STUDIES ON GREGARINESKAMM 31 



GREGARINA PTEROTRACHEAE (Stuart) Labbe 



[Figure 136] 



1871 Zygocystis Pterotracheae Stuart 1871:498 



1891 Zygocystis Pterotracheae Mingazzini 1891: 235 



1899 Gregarina pterotracheae Labbe 1899: 37 



1903 Minchin 1903: 338 



Contour of body ovoidal, typically that of the genus Gregarina, biasso- 

 ciative. Dimensions not given. Ratio LP :TL :: 1 :4; WP : WD :: 

 1 : 1.5. Protomerite dome-shaped with slight constriction in middle. 

 Deutomerite ovoidal, well-rounded posteriorly. Epicyte unusually thick. 

 Nucleus large, spherical, one to four karyosomes. 



Cyst formed of one individual seen, embedded in muscular tissue of host. 



Coelom of Pterotrachea sp. 



Taken at Odessa. 



This species is regarded as of uncertain position because it is the first 

 species of the genus Gregarina to be found in the body-cavity of a host. 

 It is the only species described from the molluscs, where one would not 

 expect to find a polycystid and biassociative gregarine. This phylum cer- 

 tainly offers splendid research opportunities, if not to substantiate to repu- 

 diate the above work. 



Stuart describes in detail the motion of the species, and because I 

 believe it is the first good record of the movements of gregarines, it is 

 reproduced here, as follows: 



Die Bewegungen des Thieres sind schlangelnder Art, aber neben den Hauptcontractionen, 

 als deren Resultat die Vorwartsschiebung der Gregarine erscheint, bemerkt man eine Reihe 

 partieller Contractionen, welche die ausseren Contouren des Korpers wellenformig umandern. 

 Bei diesen Contractionen wird die weiche innere Kornermasse bin und hergeschoben und 

 nimmt die durch die partiellen Gestaltanderungen des contractilen Schlauches gebildeten 

 Innenraume ein. Der Nucleus folgt diesen Bewegungen in beschranktem Masse mit. 



LIST OF SPECIES FOUND IN THE CLASS CRUSTACEA OF THE PHYLUM 

 ARTHROPODA 



PARASITE HOST 



DIDYMOPHYrDAE 



Didymophyes longissima (von Siebold) Frant- Gammarus ptdex von Sieb. 

 zius Orchestia littorea 



GREGARTNIDAE 



Uradiophora cuenoti (Mercier) Mercier Atyaephyra Desmaresli Millet 



Type species 



Pyxinoides balani (Kolliker) Tre"gouboff Balanus pusiUus Ecker 



Type species B. lintinnabulum L. 



B. amphitrite Darw. 

 B. eburneus Gould 

 Pyxinoides cthamali (Le"ger and Duboscq) 



Trgouboff Cthamalus stettatus Ranz. 



