of the Fishery Board for Scotland. 



317 



Notes on some Brackish-Water Species. 



But while advantage is being taken of the opportunities that from time 

 to time occur for continuing and extending the investigation of the fresh- 

 water fauna of Scotland — an investigation that is becoming of some 

 importance in view of the increasing interest in the Inland Fisheries of 

 our country — some attention has also been given to those aquatic forms 

 that occupy the ' borderland ' between what are truly fresh-water and 

 truly marine conditions. The fauna of this ' borderland ' is, especially in 

 some of its aspects, peculiarly interesting to the biologist, as it is there, if 

 anywhere, he is likely to meet with transition forms of life. 



The marshy brackish-water shores of the Clyde, to the west of 

 Langbank on the south side, and Dumbarton on the north side, have 

 recently been partially examined, and also some marshy ground in the 

 vicinity of (Jlachland Point, Arran. The names of the organisms obtained 

 at these three localities are not included in the Table of distribution, as 

 that Table is restricted to the fauna of the fresh- water lochs, but these 

 names are given hero instead. Only the names of the Crustacea, however, 

 are given, which are as follows : — 



Gammarus locusta (Linne). — Very common in pools at the roots of the 

 dense vegetation on the shore to the west of Dumbarton. 



Jeer a albifrons (Montagu). — In the same locality with the Gammarus, 

 but not common. 



Sphceroma (?) rugicauda, Leach. — Also occasionally observed with the 

 Gammarus. 



Eurytemora lacinulata (Fischer). — Near Langbank, in brackish water. 

 Cyclops Msetosus, Kehberg. — Near Langbank, in the same localities as 

 the last. 



Cyclops Mcuspidatus, Claus ; var. LubbocJcii, Brady. — In brackish water 

 at Langbank, and near Dumbarton ; frequent. 



Cyclops equoreus, Fischer. — Near Langbank ; not common. 



Tachidius Uttoralis, Poppe. — Near Dumbarton ; not common. 



Delavalia palustris, Brady. — In brackish water on the shore near 

 Dumbarton. 



Canthocamptus palustris, Brady. — In brackish water near Langbank, 

 and also near Dumbarton. 



Cantliocamptus hirticornis, T. Scott. — Near Langbank ; not common. 



Laophonte Mohammed* Richard. — In brackish water near Langbank ; 

 frequent. 



Platychelipus Uttoralis, Brady. — Near Dumbarton ; not common. 

 Cyclocypris serena, Koch. — Near Langbank, in brackish water. 



* Laophonte Mohammed, Richard. — This secies was described by Dr Richard of 

 Paris, in 1891 (Mem. Soc. Zool. France, vol. iv. p. 526, pi. vi. figs. 1-15 (separate 

 copy) ) ; it had been obtained in salt lakes in Algeria. In November 1895, 

 Mr D. J. Scourfield of London recorded its discovery in a marsh at Barmouth 

 Junction, North Wales (Jour. Quekett Microscop. Club. vol. vi. s. ii. p. 136, pi. viii. 

 figs. 3-9 (separate copy) ), and these two records and the present one seem to be all 

 the information we at present have concerning the distribution of the species. I 

 may mention that, though the Clyde specimens are identical with those from North 

 Wales, as figured by Mr Scourfield, they differ somewhat, especially in the structure 

 of the first swimming feet, from Dr Richard's description and drawings. I therefore 

 sent a few of the Clyde specimens to Dr Richard, and he, in a very friendly note to 

 me concerning them, says that in his opinion they are of the same species as that 

 described by him, and that the difference observed in the Clyde specimen may be 

 accounted for by the difference in the habitat — that they are simply a northern form 

 of the species described by him. 



