372 MR JAMES MURRAY ON A NEW FAMILY 
between the rostrum and the cesophagus. The posterior portion of this mass is, from 
its position and its connection with the antenna, regarded as the brain, but its outline 
could not be traced. Between the mastax and the stomach are two clear gastric glands, 
which meet on the ventral side. 
Habits.— Of tireless activity. It creeps without ceasing on the stems of algze and 
mosses, feeding all the time. Its mode of feeding is unlike that of any other Bdelloid, 
though Adineta resembles it in some respects. A biting action is continually repeated. 
In this the rostrum takes part. The food is caught between the rostrum and the 
lower lip, and pushed close to the mouth by the bending down of the rostrum. The 
cilia of the mouth, working downwards, catch the food that is thus brought near and 
sweep it into the gullet. The brush of cilia on the rostrum contributes to the action by 
sweeping downwards also, and to some extent compensates for the lack of dises. It was 
never seen to pause or rest, as other Bdelloids do occasionally. 
The deposition of the egg was on one occasion seen. The animal was fully con- 
tracted. When the ege was almost completely passed out, the end which still remained 
in the aperture was seen to be surrounded by a cireclet of clear spherical bodies. Most 
of these adhered to the egg when it separated, but a few remained attached to the 
aperture (Plate I. fig. d). 
Variation.—Only one species of the family is known with certainty. The lack of 
corona deprives us of several characters of great service in distinguishing species of 
Philodinadze. Various forms of spurs have been seen in Microdinade, but it is not 
yet clear whether any of these belong to distinct species (Plate II. figs. g to J). 
The jaws also differ in different examples. While agreeing in general features, the 
degree of development of the loops of the manubrium varies greatly in different 
individuals. Some show no trace of any loops, while others have three well developed, 
two on the outer side and one on the inner, passing behind the teeth. 
Habitat.—At the margins of large lakes and of clear hill lochs, also occasionally in 
pure running water. 
Discovered in Loch Vennachar, 20th May 1902, on the occasion of the visit of the 
Scottish Natural History Society, as guests of Sir Jonn Murray; Loch Ness and 
Loch Morar, 1908; hill lochs on Carnahoulin, Fort-Augustus, 1904; Loch Treig, 
December 1904. Very abundant in Loch Vennachar and frequent in Loch Ness. 
PHILODINADE. 
Classification.—The Ehrenbergian division of the Philodinade into genera dis- 
tinguished by the presence or absence of eyes, and by the position of the eyes when 
present, has long been recognised as artificial. In those genera unrelated species are 
brought together, and closely related species are separated. Suggestions for a more 
natural classification have been made, notably by Minx, but none have been generally 
