ue 
40 DIATOMACER. 
Sun-Famity—SCHIZONEMA—con. 
No. Name. Locatiry. OccuRRENCE. 
CoLLETONEMA, Bred. 
43 EXIM PLA) .ieole|| MIOStY Mes wns oie a ee arelele o's July ’75...... c 
9 neglectum, Zhw..,.| Lache Lane ............ March ’72..ve 
49 vulgare, Thw....... Helsby Marsh cisc). sacs. March ’72....r 
ScH1zonEMA, Ag. 
11 cruciger, 7. sp. ....| Helsby Marsh .......... March ’72 ...r 
12 helmintosum, G'reg..| Helsby Marsh .......... March ’72..vr 
35 obtusum, Chauwv. ,..| Puddington Marsh ...... June ’75....V Tr 
FAMILY XIX.—ACTINISCEZ. 
Dicryocua, Lam. 
36 Gracilis, Ehr....... Estuary of Dee.......... July 775..." P 
It is doubtful if this form is a Diatom. I should have 
placed it with the Radivlaria if it had not been for the fact 
that, when found in the fresh state, it is always composed of 
two valves, which enclose a space. 
DOUBTFUL GENUS. 
Evcampta, Ehr. 
14 Zodiaces, Ehr...... Connah’s Quay.......... Mayet. cd. as Yr 
I have placed this beautiful form last in the list on account of 
our present ignorance as to its exact position amongst the 
Diatomacese. In some respects it ought to be near Biddulphia 
or perhaps Meridion. Its nearest affinity however, to my mind, 
is in the beautiful genus Corinna, found in the Jutland deposit, 
and which has been described by Hurserc, Hucampia was 
found on the surface of the Estuary of the Dee, in 1872, in such 
abundance, that on taking up a glassful of water the forms 
gave the water quite a greenish tinge. It was again found 
abundantly in 1875, but it does not seem always present, and 
perhaps weather and sunshine may partly account for this 
fact. In a fresh state the form presents the appearance of a 
complete corkscrew with many turns, and may be seen revolving 
