E. RAY LANKESTER, ON GREGARINIDA. 93 
ably, without assigning any justification of such a procedure. 
There appears to “be no reasonable ground for objecting to 
the separation of the unilocular forms from the rest of the 
Gregarine. In addition to the absence of any septa dividing 
them into distinct chambers, they differ so much from the 
other Gregarinze in their general form and habit, that there 
is, 1t will be allowed, sufficient pretext for placing them pro- 
visionally i in a distinct genus. 
Ruyncopra Hetmintua. Diesing. 
Protozoa symphyta, Stein. 
Animals composed of a double membrane, enclosing minute 
granules and a vesicle; frequently provided with a prehensile 
or suctorial (?) appendage. 
Genus, Monocystis, Stein. Unilocular. 
Syn. Gregarina, Kolliker, Diesing, &c. 
Zygocystis in part, Stein. 
1. M. Lumbrici, Henle and Lieberkithn. Lumbricus. 
Syn. Zygocystis cometa, Stein. 
Monocystis agilis, Stein. 
- cristata, Schmidt. 
BE magni, ‘Schmidt. 
‘i nematoides, Schmidt. 
i porrecta, Schmidt. 
Lumbrici olidi, Schmidt. 
Gregarina Lumbrici, Bruch. 
2. M. Sipuncult, Kolker. Sipunculus. 
Syn. Zygocystis Sipunculi, Stein. 
M. Holothurie, Schneider. Holothuria. 
M. Senuridis, Koll. Szenuris. 
Syn. Zygocystis Senuridis, Stein. 
eo 
Enchytrei, Koll. Enchytreus. 
. Spionis, Koll. Spio. 
Terebelle, Koll. Terebella. 
. Nemertis, Koll. Nemertis. 
Planaria, Schultze. Planaria. 
Pachydrilli, Claparéde. Pachydrillus. 
. Phyllodoce, Claparéde. Phyllodoce. 
12. M. pellucida, Koll. Nereis. 
Syn. Greg. Nereidis, Leidy. 
13. M. Serpule, Lankester. Serpula. 
