34
THE ESSEX NATURALIST
mens were seen in catches made in the Colne Bar area in 1962
and 1965.
Galatheidae
Galathea strigosa (Linne) Squat Lobster
Of rare occurrence only in the Blackwater benthos. Single
specimens were taken in dredge hauls at stations TL.2 and N.3
in 1960, and one 'berried' female from station C.2 in 1965.
PORCELLANIDAE
Porcellana longicornis (Linne) Long-clawed Porcelain Crab
This species is only found below low water mark in the Black-
water. It was quite common during 1960, being most numerous
on clean shelly bottoms such as at station TL.4 where up to four
specimens per 0.1 m2 were recorded. A 'berried' female was re-
corded in August and the conspicuous planktonic larvae in June-
August 1960. The species declined markedly in 1961 and was not
recorded after the end of 1962. The last record came from the
Colne Bar area at the mouth of the Blackwater in May 1962.
None were recorded in the bottom surveys of 1963, 1964 or 1965.
Paguridae
Eupagurus bernhardus (Linne) Hermit Crab
Recorded from more than half of the bottom sampling stations
during 1960, being mainly found on clean shelly bottoms. Also
recorded by Walne (1956) from Stone to the mouth of the Colne
in his survey of March 1950. Other records date back to Cole
(1888). From the records of the present investigation it would
appear that the species increased in abundance after 1960 but
declined in 1963 following the severe winter. It was still reason-
ably common in 1965.
Corystidae
Corystes Cassivelaunas (Pennant) Masked Crab
Only two records; from dredge and trawl hauls around
Bachelor's Spit (19.7.1962). The species may be common on the
off-shore sand banks.
Cancridae
Cancer pagurus Linne Edible Crab
Occasionally obtained in trawl hauls, mostly in the Colne Bar
area and off-shore. Not common.
Portunidae
Portunus marmoreus Leach Swimming Crab
Regularly obtained in trawl samples in 1960. Common and
widespread in 1965. Many specimens infected with the parasite
Sacculina carcini.