AND TWELVE NEW SPECIES OF ROTIFERA OF THE ORDER BDELLOIDA. 379 
suggestion is the fact that though it will not feed, it does not appear to be uneasy In 
the glare of the microscope lamp. 
Habitat.—In lakes and ponds. Bottom of Loch Rannoch, at depth of 9 or 10 feet, 
April 1902. Abundant in pond near Fort-Augustus, January 1904. It thrives well 
in tightly corked bottles, and may continue in them for months. 
Callidina armata, n. sp. (Plate VI. figs. 10a to 10h.) 
Specific characters.—Large, massive. Corona broader than trunk. Rostrum short, 
broad ; lamellae small. Antenna as long as diameter of neck, clavate. A pair of tooth- 
like processes close below the mouth. Jaws relatively small, with two teeth on each. 
Stomach voluminous, reddish. Foot short, of three joints. A broad rounded fold at 
base of first joint. Spurs small, acuminate, incurved and decurved, interspace equal 
to diameter of base of spur. Foot ends in round perforated dise. 
General description.—Greatest length when creeping, ,; inch. Trunk with few 
longitudinal folds, dorsal faint, lateral deeper. All colourless, except alimentary canal. 
Food not moulded into pellets. Walls of stomach containing small reddish globules. 
Intestine roundish. Foot-glands of few cells, terminal cell largest. First  foot-joint 
marked with annular strize. Terminal joint long, dise perforated by many pores, ducts 
in common sheath. Four pairs of vibratile tags were seen. 
Resembling C. symbiotica and allied species in massive build and discoid foot, it 
may be distinguished from all other species by the ventral processes below the mouth, 
the heavy antenna, and the dorsal fold at the base of the foot. 
Habits.—Strong and active, like all the ‘symbiotic’ species. As it creeps rapidly 
about, the disc is exposed for an instant. It is a steady feeder. The function of the 
processes below the mouth could not be gathered from its actions. 
Habitat.—On water weeds growing in Loch Ness and the Caledonian Canal at 
Fort-Augustus ; although abundant during November and December 1903, it was not 
again found till December 1904, when it once more became common. The same beds 
of weeds, chiefly Myriophyllum and Fontinalis, were frequently examined during the 
intervening months without the species being once found. This may indicate that it 
has only a short season, though it is unusual for Bdelloids to have any seasonal 
limits. 
Callidina incrassuta, n. sp. (Plate VI. figs. 9a to 9f.) 
Specific characters.—Large, stout. Trunk protected by thick plates formed of a 
hardened secretion. Rostrum short and very broad, with small ciliate lamelle. 
Antenna considerably longer than diameter of neck. Neck with large process at each 
side of antenna. Corona as wide as trunk, discs large, interstice equal to half diameter 
of dise. Central papillze on discs. Foot very short, of three joints. Spurs small, twice 
