31] STUDIES ON GREGARINES—KAMM 31 



GREGARINA PTEROTRACHEAE (Stuart) Labbe 



[Figure 136] 



1871 Zygocystis Pteroiracheae Stuart 1871:498 



1891 Zygocystis Pteroiracheae Mingazzini 1891: 235 



1899 Gregarina pteroiracheae 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 Pierotrachea 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 hin 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 



didymophyidae 



Didytnophyes longissima (von Siebold) Frant- Gammarus pulex von Sieb. 



zius Orchestia littorea 



GREGARINIDAE 



Uradiophora cuenoti (Mercier) Mercier Alyaephyra Desmaresli Millet 



Type species 

 Pyxinoides balani (Kolliker) Tr^goubofF Balanus pusillus Ecker 



Type species B. tintinnabulum L. 



B. amphitrite Darw. 

 B. eburneus Gould 

 Pyxinoides cthamaii (L6ger and Duboscq) 



Trdgouboff Cthamalus sieUalus Ranz. 



