M98 
Mer. Lav. 
XV.—On a New Family and Twelve New Species of Rotifera of the Order 
Bdelloida, collected by the Lake Survey. By James Murray. Communicated 
by Sir Joun Murray, K.C.B., F.R.S. (With Seven Plates.) 
(MS. received January 13, 1905. Read January 23, 1905. Issued separately March 38, 1905.) 
INTRODUCTION. 
The new species here described were found in the course of the work of the Lake 
Survey on Loch Ness and other Highland Lochs. Half of the number were found in 
lakes, though they are not exclusively lacustrine, three in ponds, two from moss growing 
on the shores of Loch Ness, and one in a stream running into Loch Ness. 
Structure.—A short account of the structure of a typical Bdelloid will be necessary, 
in order to render intelligible the terms used in the descriptions. A Bdelloid is a 
Rotifer which can creep like a leech or caterpillar. The body is segmented, and 
consists of head, neck, trunk, and foot. The head, neck, and foot are telescopic, and 
can be completely withdrawn into the trunk. The normal number of segments is 
sixteen, but there may be more or less, the variation being chiefly in the foot. The 
head consists of three segments, the neck of three, the trunk of six. It is believed that 
the number of segments in each of those portions of the body is invariable, but two or 
more segments may be so united as to be indistinguishable. The foot is more variable, 
the number of segments, normally four, varying from one to six. Beginning at the 
anterior end, the first and second segments of the head form the rostrum. ‘The first 
has an inverted tip, from which rise the two rostral lamellee, numerous motile cilia, and 
sometimes larger tactile setee. The third segment is the oral, and bears the mouth, 
and the corona when present. The first cervical bears the antenna, and frequently a 
number of prominences. The second and third cervical have no appendages. The first, 
second, third, and fourth segments of the trunk are called the central, and form the 
broadest part of the body. The next two segments of the trunk, the pre-anal and the 
anal, together form the rwmp, which is generally clearly marked off both from the 
‘central part of the trunk and from the foot. At the end of the anal segment is the 
anus. The segments beyond the anus constitute the foot. The first joint of the foot 
commonly has the skin on the dorsal surface thickened, and often bears a rounded boss 
-or other processes. The penultimate joint bears the spurs. The last joint bears the 
toes, or the perforate disc which takes their place. The segmentation is superficial, and 
affects only the skin. When the animal is fully extended, the various organs usually 
occupy definite segments, though the arrangement is not invariable. The brain, 
-generally somewhat triangular, occupies the second cervical, but when large may extend 
TRANS. ROY. SOC. EDIN., VOL. XLI. PART II. (NO 15). 54 
