246 Records of the Indian Museum. iINon- val, 
When normally contracted it resembles a median longitudinal 
section of a cone in outline. In length an adult individual can 
extend instantaneously from 0°5 mm. to 2°0 mm. The integument 
is colourless and transparent and the rings on the cuticle very 
natrow. ‘The tentacles are extremely short and have a bluntly 
rounded tip; they are soft and apparently devoid of cuticle; when 
the animal is fully extended they have the appearance of being 
mounted on short peduncles. The mouth opens between them at 
the base of a depression which becomes crateriform when the 
proboscis is fully retracted and the whole animal fully extended. 
There are two eyes situated on the anterior half of the dorsal 
surface some distance behind the base of the tentacles; the eyes 
are directed forwards and outwards; they are black in colour. 
Fic. 1.—Chitinous armature of intromittent organ of Caridinicola indica. 
A.—The entire armature, very highly magnified. 
B.—The terminal cup, still more highly magnified. The stem or intermediate 
portion and the basal funnel are represented in optical section. 
When the animal is fully contracted the posterior sucker some- 
times becomes almost heart-shaped, but as a tule it resembles 
the figure formed by a straight line the extremities of which are 
curved upwards through the greater part of a circle, the distance 
apart of the incomplete circle thus formed varying with the state 
of contraction of the animal. 
Alimentary canal.—The mouth opens into an elongate eylin- 
drical but highly muscular pharynx (oesophagus) which can be 
thrust out bodily to nearly half the length of the animal. The tip 
of this organ is surrounded by a circle of minute prominences on 
each of which a sense-organ provided with a minute chitinous tooth 
is situated ; the whole ring is folded inwards when the proboscis 
is retracted. Strong, almost transverse retractor muscles, are 
