A HISTORY OF SUFFOLK 



/. viridis (Slabber), a much more slender species, with the pleon apically much less clearly tridendate, 

 was sent to me by the late Dr. Sorby, F.R.S., from the mouth of the Orwell, In the tribe Asellota, 

 family Asellidae, the universally distributed freshwater species Astllus aquaticus (Linn.) was found 

 abundant in a wide ditch near Oulton and in Kirkley Run, Lowestoft. The tribe Epicaridea is one 

 in which nature, like the giants piling Pelion uf>on Ossa, plants shrimps upon shrimps. It contains 

 only crustaceans parasitic or semi-parasitic upon crustaceans. In Suffolk the abundant Pandalus 

 montagui frequently harbours under its abdomen or pleon the lop-sided prolific Hemiarthrus ahdom'i- 

 nalis (H. Rathke) with her closely attached, small, symmetrical mate. This isopod is said to frequent 

 impartially ten or eleven different species of shrimps or prawns. Metzger records it under the 

 preoccupied name Phryxus as taken in 23 fathoms south-east of Yarmouth on Hippolyte pusiola.^ 

 By some oversight he does not include this locality among the places of capture for the host itself, 

 which, as already explained, is now called Spirontocaris pusiola. 



In the tribe Oniscidea, Messrs. Webb and Sillem ^ record only three species from Suffolk. 

 With another three here added the total assuredly falls far short of the number which will 

 eventually be found in the county. In the family Oniscidae the extremely common PorceUlo scaber, 

 Latreille, was taken at Sparrow's Nest Park, Lowestoft, and near Oulton Broad. The smooth 

 P. /aevis, Latreille, with long-branched uropods, is recorded by Mr. Webb from Ipswich. The 

 large and common Oniscus aullus, Linn., is reported from the same place by Mr. Claude Morley, 

 and has also been taken at Lowestoft. At the latter locality the much smaller and more 

 shining Philoscia muscorum (Scopoli) was found. The straight-fronted Metoponorthus pru'tnosus 

 (Brandt) has been taken at Ipswich by Mr. Webb, who further records from the same locality 

 Armadillidium vulgare (Latreille) of the family Armadillidiidae. This so-called pill-woodlouse, which 

 is not always so common as its specific name suggests, was taken variously coloured at Oulton 

 Broad, and in one instance alive on the sands between tide-marks at south beach, Lowestoft. 



The Amphipoda, like the Isopoda, have sessile eyes, and between the headpiece and the pleon 

 have seven segments of the trunk articulated and uncovered by any carapace. Unlike the Isopoda 

 they have their breathing organs, not in the pleon, but connected with the limbs of the central 

 trunk or peraeon. In the tribe of Amphipoda Gammaridea the pleon is almost always strongly 

 developed, its first three segments as a rule carrying each a pair of pleopods, each pleopod having 

 two many-jointed branches, and each joint of the branches being furnished with a couple of plumose 

 setae. To these swimming-organs succeed on the next three segments three pairs of uropods, in 

 which the branches are stiff, not many-jointed, the terminal segment or telson being as usual without 

 appendages. From this vast tribe Metzger reports Amathilla sahinei (Leach), as taken in 

 16 fathoms south-east of Yarmouth." This species, which belongs to the family Gammaridae as 

 now restricted, was named Gammarus sahini by Leach in 1819, but it has borne several other 

 names, earlier and later than those given by Leach, and should now be called Gammarellus homari 

 (Fabricius).^' By its carinate body and feebly emarginate telson it may be distinguished from the 

 common fresh-water amphipod Gammarus pulex (Linn.), which has the body not carinate and the 

 telson cleft. The latter occurs in Kirkley Run, as in almost all similar situations throughout the 

 kingdom. From the Gammaridae the Talitridae are distinguished by having no palp to the man- 

 dible and by having the third uropod usually single-branched. Talitrus saltator (Montagu), the 

 sandhopper, though not specially recorded for Suffolk, may be trusted to occur on all our sandy 

 coasts, A much more rarely observed species, Talorchestia brito, Stebbing, proved to be plentiful 

 at south beach Lowestoft, in May 1907, The relationships of these genera are rather intricate. 

 The male and female of Talitrus and the female of Talorchestia have the first legs simple and the 

 second feebly chelate. The female of the shorehopper Orchestia has the first legs subchelate and 

 the second feebly chelate. The males of Talorchestia and Orchestia have the first legs subchelate 

 and the second also subchelate, but in a much more powerful degree. Hence a new species in 

 these genera cannot easily be assigned to its proper genus unless both sexes are known. In the young 

 male of Talorchestia brito the first legs or gnathopods are still simple like those of the female, while 

 the second gnathopods undergo various changes before reaching their final form. Corresponding 

 changes have been described in detail for the young male of Talorchestia deshayesii (Audouin), one or 

 two specimens of which occurred on the same beach at Lowestoft, distinguishable by their dark 

 eyes and (when alive) by the rows of spots on the pleon." Of neither species were full grown males 

 captured. The eyes of T. brito are white, with dark pigment showing through the centre, the 

 body colouring, purple markings on a ground of pale orange and white, making this little skipper 

 difficult to see when it settles on the sand, after its many long and rapid leaps, first in one direction 

 and then in another. It was first observed in North Devonshire, and has since been recorded from 

 Gironde in France. From the family Jassidae, which are not burrowing but domicolous, yassa 



" Nordsee/airt Pomm. 285. '* The British WoodRce (1906). " Nordseefahrt Pomm. 281. 



" Dos Tierreich, Amph. Gamm. (1906), 21, p. 287. " Ibid. 546. 



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