182 MR JAMES MURRAY ON 
view it is seen that the sides are flat and parallel in the middle, with sloping portion 
making about the same angle to the front and back. The posterior sinus is concave, 
of moderate size, the anterior small. A slight ridge marks the middle of the back. 
The facets are symmetrically arranged on each side of this; they do not break the 
median line as shown by Miss Guascorr. There are about nine distinct facets on each 
half of the lorica, and they are in three rows parallel with the median line. 
Miss Guascorr considers it a rare species, and it is so in Scotland. It has only 
been found in two lochs in Scotland, Lochs Ness and Morar. Not very abundant when 
gathered, it increased greatly during a whole winter, in tightly corked bottles. 
PLa&soMAD&. 
The confusion of the synonymy among the species of this family is, I imagine, 
without parallel among Rotifers. This has now been pretty well sorted out, but while 
it prevailed it was found ditticult to name most of our species, so the distribution in 
Scotland is not traced. 
Plesoma triacanthum (BerGENDAL) (3). (Plate VI. figs. 28a, 280.) 
Though I have recorded under this name a three-spined Plasoma found in one or 
two lochs, there is some doubt as to its being that species. There has since been found 
in a pond in the same district a smaller animal which agrees more closely with 
BeRGENDAL’s and Lrvanper’s figures. Fig. 28) is the animal found in the lochs; 
fig. 28a is the smaller species, probably P. triacanthum; both are drawn to the 
same scale. 
ANAPODID&. 
Some authors (10, 30), have doubted the specific distinctness of the two alleged 
species of this genus, and those who admit both, as WrBER (52), agree that they are 
separated by very minute characters. 
Being unable to decide to which species our animal should be assigned, or to find 
out which of the two names, both of which were bestowed in the same year, has 
priority, I put it under that which it most resembles. 
ANURAADA. 
Eretmia cubeutes, GOssE. 
No living Kretmia has been seen, but in Loch Ness were found numerous tests, 
strikingly like Rhizopod shells.* The spines were placed as in E. cubeutes, and most 
of the tests contained the trophi of a Rotifer, in the same definite position. 
* Mr RoussE.er has little doubt these are Rhizopod shells, into which Rotifers have somehow got ; but they are 
quite different from the only Rhizopod (Huglypha alveolata), of similar form, known to me. 
