i897-9 8 -] The Upper Elf Loch, Braids. 371 



circumstance was the occurrence in the gathering of certain 

 Entomostraca studded with an Epistylis — a ciliate infusorian 

 allied to Vorticella. Of this remarkable combination there 

 were numerous examples. The crustacean most particularly- 

 favoured in this respect was Cyclops strenuus, one of the 

 species possessing long seventeen-jointed antenna? ; and the 

 infusorian clustered upon these antennae from end to end, 

 besides clinging to each side of the copepod's body, and even 

 to the extremity of its long forked tail. Epistylis differs 

 from Vorticella in being branched, with the calyces borne on 

 short, non-contractile stalks ; and it was a remarkable sight 

 to witness a Cyclops with a hundred or more of these in- 

 fusorians attached to it, while the young free-swimming 

 " buds " of the Epistylis revolved round the crustacean. This 

 case is not an uncommon one, the conditions requisite for its 

 production being a shallow piece of water with a quantity of 

 decayed or decaying vegetable matter covering the bottom. 

 The infusorian thus readily joins itself to the crustacean, and 

 neither seems to suffer from the strange " attachment." The 

 Epistylis so attached was E. anastatica ; but another species, 

 E. leucoa, was found on a water-bug, as well as on the un- 

 protected portion of the body of a caddis-worm. 



The only addition to the filamentous algae during the past 

 year was Draparnaldia glomerata, which was rather scarce, — 

 indeed, with the exception of two or three of the commoner 

 species of Spirogyra and Oscillaria, the members of this group 

 are conspicuously absent in the Elf Loch. It is otherwise, 

 however, with the motile or unicellular algae, which are fairly 

 abundant numerically, though not generically. Yet Volvox 

 globator was not nearly so plentiful in 1897 as in the year 

 previous ; while in the present year, so far as yet observed, it 

 is still scarce. This interesting alga is rather mysterious in 

 its appearances and disappearances, and it almost seems as if 

 some phases in its life-history were not yet perfectly under- 

 stood. Our knowledge of the whole group of the motile algae, 

 indeed, is still in a very unsatisfactory condition. Saville 

 Kent, in his ' Manual of the Infusoria,' regards Pandorina, for 

 example, as synonymous with Eudorina ; while Uroglena, 

 Syncrypta, and some others, are said by him to be probably 

 stages of development of Volvox or Pandorina. Some progress 



