28 
Transactions of the Society. 
projection curved to one side. The mouth was anterior, eccentric, 
and was followed by a short, narrow, conical gullet, without any 
cilia or rod apparatus. The macronucleus was small, oval, and 
situated in the anterior half of the body. The contractile vacuole 
was very large and situated near the posterior end. The anal 
aperture was postero-terminal, in a slight indentation of the 
posterior margin of the body. 
The form differed however from the type, as described and 
figured by the original authors, in the following features : — The 
anterior and posterior margins of the body were not regularly 
rounded ; there was no tuft of longer cilia at the posterior end ; the 
pharyngeal tube did not extend to the centre of the body, but only 
a short distance behind the anterior end ; the macronucleus was 
proportionately much smaller and situated in the anterior half of 
the body. All these features give the form examined by me a 
distinctive look, but do not justify, in my opinion, the creation of 
a new species for it. 
Family Actinobolina Ehrbg. 
Genus Coleps Nitzsch. 
Coleps kenti sp. n. 
Forms closely resembling C. hirtus were met with in August 
1918, but differed from the latter in being proportionately much 
broader, and in the absence of apical projections and posterior 
spines. Kent {19) also had observed forms “ in which no cusps 
whatever were developed at the posterior extremity, the size, 
quadrangular corrugation, and deeper longitudinal lines or furrows 
being, in common with all other essential structural details, iden- 
tical with what obtains in C. hirtus. . . . While the comparative 
length and breadth in the examples examined averaged in most 
instances the proportions of two to one, much shorter and almost 
subspheroidal specimens were not unfrequently encountered.” He 
however thought that “ this well-marked variety should perhaps 
be properly referred to the genus Plagiopogon.” But the genus 
Plagiopogon was founded by Stein for Coleps-Wks forms which, 
though not possessing apical or posterior spines, are only longi- 
tudinally furrowed, and in which the surface is not marked off 
into quadrangular areas and does not bear a coat of mail as Coleps 
does. The form encountered by me is practically the same as that 
described by Kent, and regarded by him as a distinct variety of, or 
a most closely allied species to, C. hirtus, except for the fact that 
in the specimens that came under my observation, I did not find 
the proportion of length to breadth as two to one, the average 
measurements being 52yit long and 39 p broad. For the reason men- 
