336 



OBSERVATIONS ON THE PLANKTON OF LOOE POOL. 



Date 

 and Weather. 



Temperature. 



1899. 

 29th June. 



Wind S.W., 

 squally, sky 

 OTercast, 

 dull. 



Variations in 

 the tempera 

 ture of the 

 water. 



Surface 65°F 



27th July. 



Wind E., 

 squally, un- 

 settled. 



Midwater 



65°P 

 (IH feet) 



Bottom 



63-6°F 



(23 feet). 



Surface 73°F 



Takings. 



Eucopepoda. Cyclops strenuas. 



Phyllopoda. Daphnia reticulata. 



D. longispina. 



EucopepoJa. Cyclops strenuus. 



Phyllopoda. Daphnia reticulata 



D. pulex. 



D. longispina. 



Eucopepoda. Cyclops strenuus. 



Both sexes fairly numerous. Only 

 a few females with ova attached. 



Faii'ly numerous. A few females 

 with a single egg in the brojd- 

 pouch, and a very few carrying 

 embryos were also noticed. 



Adult specimens scarce. A few 

 recently hatched specimens of the 

 same species also present. 



Not quite so numerous as in the 

 surface gathering. The male 

 specimens of this species very 

 scarce at this depth. 



Abundant. Those with ova and 

 embryos in the brood-pouch were 

 in the same stages of development 

 as those recorded in the surface 

 gathering. 



Three specimens detected in this 

 gathering. 



Very numerous Only a very few 

 of these had ova in an eai-ly 

 segmenting stage in the brood- 

 pouch. Not more than twelve 

 specimens were each carrying an 

 ephippium. 



Both sexes abundant. No females 

 with egg-sacs attached. 



Phyllopoda. Daphnia reticulata, i Not vei'y numerous 



D. pulex. 



D. longispina. 



Eucopepoda. Cyclops strenuus. 



C. Thomasi. 

 Phyllopoda. Daphnia reticulata. 



D. longispina. 



Six female specimens present. 



Exceptionally abundant. The 

 majority of these had one or more 

 ova in an early stage of develop- 

 ment in the brood-pouch. 



No male specimens of Phyllopod 

 detected in any of these gatherings. 



Females abundant, males scarce. 

 A few of the females of this 

 species had egg-sacs attached. 



Only a few females present. 



Adult females fairly numerous. 

 Young specimens scarce. 



Adult females scarce, 

 specimens abundant. 



Young 



