178 MR JAMES MURRAY ON 



long foot has one segment more than is usual in the genus. The large figure (15a) on 

 Plate IV. shows the foot partly retracted ; the smaller figure (156) shows the true pro- 

 portions. The corona is of the form usual in the genus. The discs bear each a central 

 tuft of motile cilia, corresponding to the central setae of Philodina, etc. The collar is 

 more worthy of the name than usual, consisting of a long pendant flap, very broad in 

 the lateral part. Intestine pear-shaped. Reproduction viviparous. Loch Ness and 

 the Caledonian Canal. 



Adinetad^e. 



A. tuberculosa, Janson (24). (Plate IV. fig. 14.) 



This species has been found among hepatics at the margins of one or two lochs, and 

 in other situations. The most distinctive character of the species is the series of coarse 

 papillae which cover part of the body. 



All the Scottish examples differ from Janson's description in one important 

 particular. Janson says that the tubercles cover the whole body, with the exception of 

 the last foot-segment. All the examples I have seen have no tubercles on the central 

 segments of the trunk. On the adjacent neck-segment and preanal the papillae are 

 largest, and diminish in size forwards and backwards from these segments, but remain 

 large in several rows in the middle of the head. Their absence from the central 

 segments is the more remarkable, as, in most species possessing a similar armature, this 

 is confined to these very segments, or is strongest there and diminishes or disappears on 

 the neck and foot. 



The spurs also differ from those figured by Janson, which are simply tapering, 

 acuminate and acute. In our specimens they are enlarged from the base upwards for 

 about two- thirds of their length, then shortly acuminate. 



Margins of Lochs Ness and Earn. 



NoTOMMATAD^E. 



Albertia intrusor, Gosse. (Plate V. figs. 24a to 24c/.) 



I n every example of Stylaria lacustris which I have examined under pressure, one 

 or more parasites of the genus Albertia were invariably present. The species comes so 

 near A. intrusor, Gosse — although Gosse's figure gives no idea of the great posterior 

 enlargement — that I identify my animal with that species. 



In situ in the gut of the worm they were readily detected by their motions, alternately 

 extending and contracting. When set free by the death of the host their behaviour 

 was remarkable. They crept along in Bdelloid fashion, although no hold appeared to be 

 taken by the toes. The head-grip was loosened, the posterior part of the body apparently 



