182 MR JAMES MUERAY 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 Glascott. There are about nine distinct facets on each 

 half of the lorica, and they are in three rows parallel with the median line. 



Miss Glascott 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. 



Plcesomad^e. 



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 difficult to name most of our species, so the distribution in 

 Scotland is not traced. 



Plcesoma triacanthum (Bergendal) (3). (Plate VI. figs. 28a, 286.) 



Though I have recorded under this name a three-spined Plcesoma 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 Levander's figures. Fig. 286 is the animal found in the lochs ; 

 fig. 28a is the smaller species, probably P. triacanthum ; both are drawn to the 

 same scale. 



ANAPODIDiE. 



Some authors (10, 30), have doubted the specific distinctness of the two alleged 

 species of this genus, and those who admit both, as Weber (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. 



Anur^ad^;. 



Eretmia cubeutes, Gosse. 



No living Eretmia 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 Rousselet has little doubt these are Rhizopod shells, into which Rotifers have somehow got ; but they are 

 quite different from the only Rhizopod {Euglypha alveolata), of similar form, known to me. 



