THE ROTIFERA OF THE SCOTTISH LOCHS. 177 



Var. bullata, n. var. (Plate III. figs. 10a to 10c/.) 



Distinctive characters. — Less robust than the type, head and foot more elongate, 

 colour yellowish. First joint of foot with eight prominences, in three rows : first row, 

 nearest base, of four equal hemispherical processes, two lateral, two dorsal ; second row, 

 of two lateral processes, like those of the first row, and one median dorsal, transversely 

 elongate, as though formed by the junction of two hemispherical processes ; third, a 

 single very prominent median process. 



The very ornate foot is the most important character of the variety, but the 

 narrower form, longer extremities, and yellowish colour all further distinguish it from 

 the type. A few examples were sent to Mr Bryce, who succeeded in finding them, 

 and after some study suggested that the form belonged to C. habita. In deference to 

 his opinion, I subordinate it to that species as a variety. 



Among submerged moss on rocks at the margin of Loch Treig, December 1904, 

 abundant. Eecently found also in India. 



Rotifer. — Viviparous, toes three, eyes present or absent. When eyes are present 

 they are in the rostrum. All the species in this list possess eyes, except R. longirostris 

 (Janson) and R. socialis (Kellicott). 



R. neptunius, Milne (35). 



This is closely related to R. trisecatus (51), which it nearly equals in length, but 

 is narrower. I can only see two joints in the long spurs ; in R. trisecatus there are 

 three. The ventral toes are of extraordinary length, when fully extended even 

 exceeding the spurs, but appear to be only two-jointed. The median dorsal toe 

 appears shorter ; if it be as long as the others, it is habitually less extended. The 

 teeth on the jaws are of only moderate thickness. 



R. trisecatus, Weber (51). (Plate V. figs. 20a to 20c.) 



This gigantic Bdelloid was only once seen in a loch, but is known in ponds (38, 

 47). The foot is short for the genus, but of the usual five segments. The very large 

 spurs are distinctly three-jointed (fig. 20c). I have never seen it feeding, so as to 

 observe the characters of the corona. A very good distinctive mark of the species is 

 offered by the teeth (fig. 20a), which are of very unusual breadth. These are 

 better shown in Weber's original figure (51, Plate XXX.) than in his later work 

 (52, Plate 14). 



R. socialis (Kellicott). (Plate IV. figs. 15<x to loe.) 



The commonest of the parasites on Asellus. An extremely long animal, and un- 

 gainly when creeping, it assumes the form of an elegant vase when feeding. The very 



