STRUCTURE AND LIFE-HISTORY OF COPROMONAS SUBTILIS. 81 
under consideration. It is, indeed, premature to attempt 
detailed classification, for there can be no doubt that, with 
increased knowledge of flagellate life-histories, our. present 
system will have largely to be recast. I would point out, 
however, that the creature should most probably be referred 
to the family Peranemida, Klebs, and sub-family Petalo- 
monadina, Biitschh. Its nearest allies appear to be 
Petalomonas, Stein, and Scytomonas, Stein. Judging 
from the figures of this latter (S. pusilla, Stein) given by 
Klebs (28), Pl. XIV, fig. 9 a-d, there is considerable similarity 
between the two organisms. But very little is known of the 
various species of Petalomonas and Scytomonas, so that 
it is impossible to make any definite statements on the sub- 
ject. I must be content, therefore, to leave the monad in its 
present unsettled position, awaiting the work of future 
investigators. 
I propose to name this monad Copromonas subtilis, 
nov. gen. et noy. spec. ‘The systematic position may therefore 
briefly be expressed thus : 
Phylum.—P rotozoa. 
Class.—Mastigophora (Diesing). 
- Sub-class.—F lagellata (Cohn emend. Biitschli). 
Order.—Euglenoidina (Klebs). 
(? Family —Peranemida [Klebs] ). 
(? Sub-family.—Petalomonadina [Biitschh)). 
Genus.—Copromonas (nov. gen.). 
Species.—su btilis (nov. spec.) 
STRUCTURE. 
The general anatomy of Copromonas is seen in the 
accompanying diagram (text-fig. A). 
Although the organism, when seen under a low power, 
appears to be of a very simple structure—consisting merely 
of a globule of protoplasm with an anteriorly -directed 
flagellum—it possesses, in reality, considerable morphological 
differentiation, The body is more or less ovoid or pyriform, 
