THE MARINE FAUNA OF THE BLACKWATER ESTUARY 51
Scrupocellaria reptans (Linne)
Common, with S. scruposa, but perhaps more abundant where
there is less mud in the sediment.
ESCHARELLIDAE
Escharella variolosa (Johnston)
Dredged from the Blackwater, 25.5.1961.
Hippopoeinidae
Cryptosula pallasiana (Moll.)
Dredged from the Blackwater, 25.5.1961.
Alcyonidiidae
Alcyonidium gelatinosum (Linne)
Common and widespread over clean shelly and stony bottoms,
mostly below low water mark. Often obtained in large quantities
in the summer from areas at the mouth of the Blackwater.
Alcyonidium polyuum (Hassal)
Encrusting on shells and stones on clean bottoms, particularly
in the vicinity of Thirslet Creek.
Alcyonidium mytili Dalyell
On a wreck in Strood Channel, West Mersea, 25.5.1961.
Vesiculariidae
Vesicularia spinosa (Linne)
Dredged off St. Peter's Flats, 19.7.1962.
Bowerbankia imbricata (Adams)
Several specimens attached to shells on the lower shore near
Weymark's Sluice, Bradwell, 4.9.1963.
Bowerbankia citrina (Hincks)
From the shore at Bradwell, 7.1960.
Ammathia lendigera (Linne)
Usually found attached to hydroid colonies or on shells.
Thirslet Creek, 1960.
Valkeriidae
Valkeria uva (Linne)
From the shore at Bradwell, 7.1958.
Phylum ECHINODERMATA
Class ASTEROIDEA
Order Spinulosa
Solasteridae
Solaster papposus (Linne) Sun Star
Common over most parts of the area except where the bottom
is excessively muddy. Mostly obtained by dredging but some-