324 A. C. Stokes—Fresh-water Infusoria. 
bling it the pulsating vacuole is large, single, and located near 
the origin of the caudal extremity. From Litonotus pleurosig- 
ma, described by the writer in the American Monthly Micro- 
scopical Journal for July, 1884, for which it might perhaps be 
mistaken if observed only in its contracted state, it differs in 
greater extensibility of the neck and tail, in the absence of the 
funiculus between the two nuclei, and especially in the 
arrangement of the contractile vesicles, those of LZ. pleurosigma 
being disposed in two rows, one on each side of the body near 
the ventral surface, while with Z. vesiculosus they are not only 
more numerous, but are scattered throughout the body cortex 
as well as through the tail and neck. 
Reproduction is by transverse fission, the dividing plane 
passing between the nuclei which have previously separated so 
that, as fission proceeds, each part of the animalcule has a 
single endoplast. Each nuclear nodule then elongates, quite 
rapidly divides transversely, the parts separating and becoming 
subspherical with some rapidity, so that before the compietion 
of the reproductive act, each infusorial moiety possesses two 
disconnected nuclei, as did the parent. The mature infusorian 
is shown in fig. 15. 
Litonotus carinatus, sp. nov. 
the anterior body-half. Reproduction by transverse ber 
Length of body x1; to x4, inch. Habitat.—The bacterial pe 
The infusorian is represented in its dorsal aspect in fig. i 
It was obtained in great abundance on and beneath the J A 
like layer of bacterial and fangoid growths covering the ation 
of an infusion of various kinds of leaves, forming for some 10" 
the prevailing animaleule. It cannot be easily mistake 
any other species of the genus, 
