1897-98. ] The Upper Elf Loch, Braids. 375 
seven species. No representatives of either the Amphipoda 
or Isopoda have been observed, though both Gammarus pulex 
and Asellus aquaticus are frequent enough in other parts of 
the Edinburgh district. 
The greatest number of species observed in any single 
gathering was twenty-five; this gathering was collected in 
September 1897. The smallest number — twelve — was 
observed in a gathering collected in May 1896. Five species 
of the Entomostraca have been observed in every one of the 
twelve gatherings examined: the names of these species are— 
Cyclops viridis, C. bicuspidatus, Canthocamptus staphylinus, 
Cyclocypris serena, and Candona candida. Two species — 
Cyclops strenuws and Simocephalus veiulus—were observed in 
ten of the gatherings. Three species—Cyclops serrulatus, 
Alona quadrangularis, and Chydorus spheericus—occurred in 
nine gatherings.  Attheyella pygmea, Cypria ophthalmica, 
Daphnia pulex, and Alonella nana—four species—were ob- 
tained in eight gatherings. <Attheyella crassa and Alona guttata 
occurred in seven gatherings, Cyclops albidus and Cypris fuscata 
occurred in six, and Ilyocryptus sordidus in five. Cyclops 
vernalis, C. fimbriaius, Moraria Anderson-Smithi, and Grapto- 
leberis testudinarius were observed in four gatherings; while 
Canthocamptus minutus was obtained in three. The following 
eight species were each observed twice—viz., Cyclops fuscus, 
C. affinis, Canthocamptus inornatus, Attheyella Zschokkei, Piono- 
cypris vidua, Ceriodaphnia reticulata, Alona costata, and Chy- 
dorus barbatus. | 
With regard to the seasonal distribution of the Crustacea 
the following points may be noted. It has been already 
stated that five of the species obtained in the loch occurred 
in every one of the twelve gatherings examined. These 
gatherings were collected under very varying conditions of 
weather and temperature, as well as at different seasons of 
the year—for example, during the heat of midsummer, when 
the little loch was much contracted by drought and largely 
overgrown with vegetation; during the late autumn, when it 
was filled to overflowing with the autumnal rains and when 
the vegetation had to a considerable extent disappeared ; and 
also during winter, when the only way in which a gathering 
could be taken was by breaking the ice that covered the 
