January. 
F ebruary . 
A 
0 
u 
ri 
Z 
April. 
May. 
June. 
3 
1 — 1 
August. 
— 
September. 
October. 
November. 
* “ — ■ 
SlDA crystallina - 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
tn 
+4 t 3 t 9 
Diaphanosoma brachyurum 
t 
t 
t 
t 
t 
t 
t 
tf 
tic 
t2 
1*6 
ti 1 
Daphnia magna - 
t 
t 
t 
+6 
t 
ti 
ti 
ti 
t 
1*2 
1* tf 
,, atkinsoni 
ft 
ti 
t 
t 
ti t 
,, pulex - 
t 
+ 
t 
t 
+1 
t 
+2 
+3 
+4 
t 
+3 
+1 
+2 
t2 
t6 
t 
t8 
ti t7t2 
,, longispina - 
t 
t 
t 
t 
t 
t 
tl 
t 
+4 
ti 
t6 
t 
+7 
t2 
t 4 
t 
ti 
t t 5 t 
,, lacustris 
t 
t 
t 
t 
t 
t 
t 
t 
t 
,, cucullata 
t 
t 
t 
t2 
ti 
ti 
tl 
t4 
t 
Scapholeberis aurita 
t 
t2 
1*2 
1*3 
,, mucronata - 
t 
t 
t 
t 
t 
+2 
t 
t6 
t 
t5 
ti h 
Simocephalus exspinosus - 
t 
t 
+ 
t 
t 
t 
ti 
t 
t 
t ti 
,, vetulus 
t 
t 
t 
t 
t 
t 
t 
+ 1 
t 
t 
t 
ti 
t 
t 
t 
t t t 
Ceriodaphnia reticulata - 
t 
+ 
t 
t 
t 
t 
ti 
t7 
t 
t4 
tl 
tn 
tiotstj 
ti tif: 
, , megalops - 
t 
t 
ft 
t 
t 
1*2 
t8 
, , quadrangula 
+1 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t2 
t 
t4 
t t3ts 
,, pulchella 
t 
+ 
t 
t 
t 
t 
ts 
t 
+3 
t 
1 1 3 
1*6 t4tj 
,, affinis - 
+1 
t 
1*2 
ti 
t * f 
,, laticaudata - 
t 
ti 
t 
ti 
t 
ti 
t 
1*2 
ti t 
Moina rectirostris 
ti 
t 
tl 
t 
Bosmina longirostris - 
t 
t 
t 
t 
+ 
+ 
t 
t 
t 
+ 1 
tl2 
+5 
t2 
t 
t2 
t 
tl 
1* t t 
Ilyocryptus sordidus 
t 
t 
t 
t 
t 
t 
t 
*!• 
t 
t 
t 
1* t ' 
,, agilis - 
t 
t 
t 
t 
+ 
t 
t 
t 
t 
t 
t 
t 
,, acutifrons 
t 
t 
t 
t 
t 
t 
Macrothrix laticornis 
t 
t 
t 
t 
t t 
Lathonura rectirostris 
t 
+ 
t 
+ 
t 
t 
t 
+ 
t 
t 
t 
t 
t 
*1* tt 
Eurycercus lamellatus 
1- 
t 
+ 
+ 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
1* t tl 
Camptocercus rectirostris - 
t 
t 
t 
t 
t 
t 
tl 
I* titi 
,, lilljeborgii - 
t 
t 
t 
t 
u 
1*2 
Acroperus harpae 
t 
+ 
t 
t 
t 
t 
t 
t 
t 
t 
t 
ti 
ti 
t 
t 
tio 
1*2 ts ts 
Alonopsis ambigua 
t 
tl 
*)■ 
Lynceus quadrangularis 
t 
+ 
t 
t 
t 
t 
t 
+ 1 
t 
ti 
t 
t 
t 
t 
1* tt 
,, affinis - 
1- 
t 
t 
t 
t 
+ 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
ti 
1* tt 
,, tenuicaudis - 
t 
t 
ti 
tl 
t 
tl 
,, costatus 
t 
t 
t 
+ 
t 
t 
t 
t 
t 
t 
ts 
*1*4 t2ti 
,, guttatus 
t 
t 
t 
t 
t 
t 
t 
t 
+ 
t 
t 
t 
t t 
,, rectangulus - 
t 
t 
t 
t 
1*2 
t 
1*4 
■1*4 t tl 
,, elegans 
t 
tl 1*1 ti 
,, rostratus 
+ 
+ 
t 
t 
t 
t 
t 
t 
t 
t 
1*3 
Leydigia quadrangularis 
t 
t 
t 
t 
t 
t- 
t 
ti 
t tt 
,, acanthocercoides - 
t 
t 
b 
t 
Graptoleberis testudinaria 
t 
t 
t 
+ 
t 
t 
t 
t 
t 
t 
t 
t2 
t tats 
Alonella excisa 
t 
t 
t 
t 
t 
t2 
t 
ti 
t 
t 
t 
t tt: 
,, exigua 
t 
t 
t 
t 
tl 
1* tt 
,, nana - 
t 
t 
t 
1- 
t 
t 
t 
t 
t 
t3 
t 
t 
t 
t 
t 
1 tt 
Peratacantha truncata - 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t5 
15 t* 3 1 ; 
Pleuroxus laevis - - 
t 
t 
t 
t 
t 
t 
*!* 
,, trigonellus 
+ 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
ti ti , 
,, aduncus - 
t 
t 
t 
t 
t 
t 
+ 
t 
t 
t 
t 
t 
*1* t 
,, uncinatus - 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
*1* 
t 
t 
t t 
Chydorus globosus 
t 
t 
t 
t 
t 
t 
t 
t 
t 
t 
ti t t 
1 J 
,, ovalis 
+ 
t 
t 
t 
t 
t 
t 
t 
t 
t 
ti 
t 
t 
>> sphaericus - 
t 
1- 
t 
1- 
t 
t 
+2 
t 
t 
+ 
ti 
t 
t 
t 
t 
t 
t 
t tt 
Anchistropus emarginatus- 
t 
1*2 1*3 ti 
Polyphemus pcdiculus 
t 
t 
+ 
t 
t 
t 
+ 
1*2 
t 
t 
t 
t7 
Total species- 
1621 
14 
'5 
25 
18 
30 
20 
35 
30 
42 
30 
45 
+s 
5° 
43 
5° 
15 3 s 5; 
Total species sexual 
— 
I 
— 
I 
- 
3 
I 
2 
3 
12 
2 
15 
1 2 
l6 
8 
27 
■25 
18 17' 
Teal sexual records 
- 
1 ! 
- 
-1 
1 
- 
5 
j_ 
SI 
3 
18 ! 
6 
34 
tS 
4 «_ 
I l 
4 S 4S. ; 
l ablc No. i. Showing seasonal distribution of Cladocera in Norfolk during 1903 and 1904 (left hand**; 
each pair, 1903; right hand, 1004). The cross indicates the occurrence of the species, and the figures the® 
sexual records for each species. The general lowness of these figures for 1904 is due to the smaller number ol 
