24 ANNALS OF SCOTTISH NATURAL HISTORY 



CLADOCERA continued. 



ist Visit, 2nd Visit, 3rd Visit, 

 July 6. July 13. Aug. 24. 



Eitrycercus lamellatits (Miiller) ... c. 



Acroperus harpce, Baird ... n.c. 



Lynceus (Alona] guttatus (G. O. Sars) . . n.c. 



quadrangularis (Miiller) . n.c. 



affinis, Leydig . . . n.c. n.c. n.c. 



ritstiats (T. Scott) . . v.r. 



,, rectangularis, G. O. Sars . r. r. 



Pleuroxus trigonellus (Miiller) . . . n.c. 



ttncinatus, Baird . . . % n.c. 



Peratacantha (Peracantha] tntncata, Miiller . n.c. 



Chydorus sphcericits, Miiller c. c. 



With the exception of Ceriodaphnia quadra ngula and Lynceus 

 (Alona} rectangularis, the species enumerated have already been 

 recorded for Aberdeenshire, but not from the district under con- 

 sideration. Ceriodaphnia qnadrangula appears to be somewhat of a 

 local species and not very common ; Lynceus (or Alona} rectangle /aris 

 is sometimes not uncommon in pools near the sea where the water 

 is slightly brackish, and has been obtained not only in the vicinity 

 of the river Ythan, but also on the Links at Aberdeen. 



I may mention that in the large recently published work on the 

 Cladocera of Sweden by Prof. W. Lilljeborg, 1 the name Alona of 

 Baird is set aside in favour of Lynceus of Miiller. The genus 

 Lynceus., instituted by Miiller in 1776, came in course of time to 

 include forms that differed so considerably from one another that a 

 revision and rearrangement of the species it contained became more 

 and more urgent. Dr. Baird took the work in hand, and one has 

 only to read his " Natural History of the British Entomostraca " to 

 see how thoroughly it was done. He broke up the old genus into 

 a number of genera, but the name which Miiller had instituted was 

 not given to any of them, yet, curiously enough, he reserved the 

 name Lynceidae for the family. In Lilljeborg's work Miiller's name 

 Lynceus is restored for that group of species to which Baird gave the 

 name of Alona. 



I may also state that Lilljeborg has altered Baird's name Pera- 

 cantha to Peratacantha. 



OSTRACODA. 



ist Visit, 2nd Visit, 3rd Visit, 

 July 6. July 13. Aug. 24. 



Cypria ophthalmica (Jurine) c. c. c. 



Cyclocypris serena (Koch) c. c. 



,, Icevis (Miiller) .... n.c. 



1 " Cladocera Suedes," von Prof. \V. Lilljeborg [Nova Acta Regire Societatis 

 Scientiarum Upsalensis, Ser. Tertioe, vol. xix. (1901)]. 



