D. J. SCOURFIELD ON THE ENTOMOSTRACA OF NORTH WALES. 137 



varies slightly from the marine form, as noticed by Prof. Brady 

 in his Monograph of British Copepoda. Recorded only from 

 pools near high water, Llanfairfechan (G. S. B.). 



The foregoing list shows that np to the present the total num- 

 ber of Entomostraca recorded from North Wales has been 67, 

 made up as follows : — Cladocera, 30 ; Ostracoda, 10 (of which 

 three are brackish water forms) ; and Copepoda, 27 (of which 

 seven are brackish). Considering the very moderate amount of 

 work that has as yet been done, these figures, at least as regards 

 the Cladocera and Copepoda, must, I think, be considered as 

 satisfactory. The comparative smallness of the list of Ostracoda 

 is no doubt somewhat surprising, but I am inclined to think that 

 it corresponds to a real deficiency in the number of these animals 

 actually living in the district. 



The list also shows a more than usually large proportion of 

 species which may reasonably be considered either as rare or 

 specially interesting. Two of the Cladocera, Ceriodaphnia pul- 

 chella and Alona affinis, and one of the Copepods, Laophonte 

 Mohammed, are new to the British fauna, while there are quite a 

 number of species, e.g., Latona seti/era, Acantholeberis curvirostris, 

 Drepanothrix derdata, Ghydorus latus, C. ccelatus, Bythotrephes 

 longimanus, Diaptomus hircus, Cyclops languidus, C. bicolor, 

 Canthocauiptus miniitus, Claus, C. Mac Andrews, and C. hirticornis, 

 which have at most only been recorded a few times in the British 

 Isles. 



It is certainly premature to make any serious attempt to com- 

 pare the Entomostracan faunas of different districts of the United 

 Kingdom, but in looking over this record from North Wales, I 

 cannot help noticing a few points in which it differs from that of 

 the district with which we are most familiar, viz., the South-east of 

 England. Among the Cladocera, some eight species appear in the 

 present list, i.e., more than one-fourth of the whole, that have never 

 been seen, so far as I am aware, in this part of the country. These 

 are Latona setifera, Ceriodaphnia pulchella, Bosmina longispina, 

 Acantholeberis curvirostris, Drepanothrix dentata, Alonopsis elongata, 

 Bythotrephes longimanus, and Leptodora hyalina. On the other 



