The distinguishing features of the common squid of British waters, Loligo forbesi, are summarized, and contrasted with those of L. vulgaris. The life-cycle and growth of L. forbesi are described, based on samples from trawl catches off Plymouth. This species seems to be an annual - young squid first appear in the trawl in late May, when their length is about 10 or 11 cm. Subsequent growth is rapid, and the males reach 30 cm and the females 25 cm by November. Spawning takes place mainly in December-January, but may continue into the spring. Neither sex survives beyond a single spawning season. Hatching of the spawn probably takes 30–40 days, and if the young squid taken in the trawl in late May hatched in the early part of the same year, a growth rate of about 25 mm/month would be required. Known growth rates for other species of Loligo are about 20 mm/month, so that indicated for L. forbesi does not seem to be impossibly high. The life-cycle is summarized in Fig. 8. There is also a summer spawning population, which grows to a rather smaller size at maturity, and which also seems to be annual.During the summer L. forbesi ranges throughout the English Channel and southern North Sea, particularly in inshore areas. In October the squid migrate farther offshore and tend to occupy the western part of the Channel.Values for total weight of squid/2 h trawl are given, on a monthly basis, for 1966–9. The largest quantities are usually taken in October and November, the highest single figure being 30.54 kg/2 h trawl, in November 1967.

A survey has been made of the bottom fauna in ca. 10–50 m along the south coast of England, using a modified anchor-dredge. Particular attention has been paid to the molluscs (both living and dead) and to the echinoderms, only larger or more conspicuous members of other groups being identified.Within the Channel there are considerable variations in temperature and other hydrographic conditions, and these are discussed in relation to their possible role as limiting factors in distribution. The fauna and bottom deposits of the different areas covered in the survey are briefly described.Distribution trends are classified as:(1) Species generally distributed in the Channel. This is the largest group, and includes three species reaching their northern limits in British waters.(2) Species confined to the western parts of the Channel.(a) Western species. Four or five species common at Plymouth in the 1920's, but now absent or very rare. Small numbers are found today only off the south Cornish coast, and those which occur in the North Sea are restricted to the north-western areas. Apart from one species, these forms are not at their geographical limits in the English Channel, and their occurrence may be partly related to the presence of ‘western’, but not necessarily Sagitta elegans, water.(b) Cornubian species. These are near the northern end of their range, and occur quite commonly off the south Cornish coast, becoming progressively less common farther up-Channel. It is suggested that their distribution is related to an intolerance of the lower winter temperatures in the more eastern part of the Channel.

A survey has been made of the biomass of the macrobenthos at twenty stations in the English Channel off Plymouth. The object was to provide a basis for following long-term fluctuations in the fauna.A brief survey of physical conditions in the area is given, and a gradeanalysis of the soil at each station has been made.Core-samples show that the sediment is shallow in many places and rock has been taken at 36 cm. or less below the surface at a number of stations.Samples totalling ½m.2 were taken at each station with a modified 'scoopsampler', covering 1/10m.2, which is briefly described.Sources of error in sampling are considered in detail. Some species may evade the sampler and others live too deep in the sediment to be taken. A comparison against a Petersen grab and a new ' suction-corer' show that the scoop-sampler does take a reasonably quantitative sample. The number of species taken in successive hauls, when plotted against the log of the area sampled, approaches a straight-line relationship similar to that obtained by Williams (1950).A statistical analysis is made of a series of samples taken at one station, and the variance between the two samples in each haul and between successive hauls calculated. At this pàrticular station the fauna in successive samples is shown to be fairly random.A sieve of 2-2 mm. mesh was employed. Compared with a finer sieve losses in terms of numbers may be quite large, but the total weight taken is little affected.

An earlier paper (Holme, 1961) described the bottom fauna off the south coast of England, as sampled by a modified anchor-dredge. Sampling was later extended to cover the whole English Channel, a further 144 stations being worked, making 311 in all. This paper describes the results of the later survey which, as previously, was concerned mainly with molluscs and echinoderms. Distribution charts for the majority of species identified are given, in which are incorporated the results of both surveys.