AND TWELVE NEW SPECIES OF ROTIFERA OF THE ORDER BDELLOIDA. 377 
trunk makes it a more elegant animal than C. Jata, the great posterior breadth of which 
imparts a clumsiness of gait as it moves. 
Habits.—In its steady, deliberate motions and mode of feeding it resembles C. lata. 
When creeping it goes steadfastly forward, increasing the length of each step by a glid- 
ing movement produced by the cilia of the rostrum. It feeds for shorter periods than 
C. lata. 
Habitat.—In ponds near Fort-Augustus, February 1904. Found among the sedi- 
ment obtained by washing aquatic mosses. It was very abundant insome ponds. When 
a portion of the sediment was put into a bottle with some water and tightly corked the 
animal continued to abound, and increased in numbers for some months, though the 
water was never changed. 
Callidina muricata, n. sp. (Plate V. figs. 7a to 7h.) 
Specific characters.—Of moderate size, narrow. Trunk with strong longitudinal 
plicee, covered with low rounded tubercles. Corona narrower than neck. Discs large, 
separated by very small interstice. Rostrum narrow, with large lamellze, which project 
- laterally. Antenna slender, length equal to half diameter of neck. Neck with large 
thickenings on each side of antenna. Brain large, elongate; no eyes. Dental formula 
2/2; border of jaws crenate. Food not moulded into pellets. Foot short, of four joints. 
Spurs slender, tapering, meeting at base, divergent, incurved. Toes, three ; large, taper- 
ing. Reproduction oviparous. 
General description,—Greatest length =, to +35 imch. Skin of trunk yellowish, 
viscous, with little extraneous matter adhering. Stomach large, its walls containing 
small dark-greyish globules. Yolk-mass with eight nuclei. Egg large, oval. Discs 
nearly touching. Border of jaws brown. 
The tubercles are of equal size, rounded, and disposed in transverse and longitudinal 
rows. They are probably permanent, and not mere hardened secretions as in C. 
merassata, but this is not proven. On the back they are hidden by the deep longitudinal 
plicee. The transverse rows, about nine on the trunk, give a false appearance of close 
segmentation. The tubercles are more obvious on the ventral side, and all over when 
fully retracted. The glands, intestine, and cloaca were normal. Vibratile tags not 
seen. Apart from the tubercles, the species may be known by the close approximation 
of the large discs and by the caliper-like spurs. 
Habits.—Very slow in its motions. It extends itself with studied deliberation, like 
Rotifer tardus, and is not often willing to feed. It feeds steadily, but only for a short 
time. On all the occasions when it was seen feeding the ventral side was uppermost, 
so that the details of the upper lip could not be seen. 
Habitat.—In the sediment of ponds, Fort-Augustus, January 1904, frequent ; 
_ Blantyre Moor. 
