THE MARINE FAUNA OF THE BLACKWATER ESTUARY 55
MOLGULIDAE
Molgula oculata Forbes
Occasional on shelly bottoms, with or without a certain amount
of mud. Recorded from stations at Thirslet and along the north
and south shores during 1960. May also include other members
of the genus.
Class COPELATA (— Larvacea)
OIKOPLEURIDAE
Oikopleura dioica Fol.
In plankton samples; mostly in June and August extending
into October 1962, and in June extending into October 1963.
Sub-Phylum VERTEBRATA
Class MARSIPOBRANCHII
Order Hyperoartia
Petromyzonidae
Petromyzon marinus Linne Sea Lamprey
Noted as uncommon in 1891 when a specimen weighing 4 lbs.
was caught at Hythe Quay on the Colne (Essex Naturalist).
Class SELACHII
Order Pleurotremata
Lamnidae
Lamna cornubica (Gmelin) Porbeagle Shark
Occasionally recorded at the beginning of the century, off
Brightlingsea, Tollesbury and Clacton (Essex Naturalist).
Scyliorhinidae
Scyliorhinus caniculus (Linne) Lesser-spotted Dogfish
Occasional records from fishermen. Caught in trawl on the
Bench Head but mostly found further offshore (1962).
Carcharinidae
Galeorhinus galeus (Linne) Tope
Fairly common. Caught in trawls on the Bench Head and
offshore (1962) and by anglers in the Blackwater. A record nine-
foot Tope was caught off Maylandsea in 1847.
Mustelus mustelus (Linne) Smooth Hound
Occasionally taken in trawl hauls. Bench Head and Swire
Hole (1962).
Squatinidae
Squatina squatina (Linne) Angel Fish
One record from Swire Hole (1962). Probably common off-
shore.