CRUSTACEANS 



1847, but that is itself a synonym of the much eadier Praunus, Leach. Metzger quotes Mysis 

 spimfera. Goes, as a synonym of Gastrosaccus sanctus, but it is now known that these two species are 

 distinct, G. spinifir having the concave hind margin of its carapace prettily fringed with eight sharp 

 denticles, which are not present in the other species. From Praunus this genus is distinguished by 

 the very great development of the side-plates in the first pleon segment. All the three species men- 

 tioned agree in having the telson apically divided. Thus they are separated from a fourth species in 

 the same family, Siriella armata (Milne-Edwards), of which a specimen was found by Mrs. T. R. R. 

 Stebbing, cast up among hydroids on the north beach, Lowestoft, in May 1907. This species has 

 a very long sharply-pointed rostrum, agreeing in this respect with S. frontalis (Milne-Edwards), but 

 separated from it by the scale of the second antennae, which in S. armata is distally much 

 narrower, and by the armature of the telson, wherein the marginal spines are less unequal and the 

 larger are separated from one another by less numerous small ones. The apical spinules are three 

 or' four in number. 



The Edriophthalma or sessile-eyed Malacostracans offer a few points of interest in the fauna of 

 Suffolk. In the order Isopoda, tribe Flabellifera, family Sphaeromidae, Mr. Claude Morley reports 

 Sphaeroma longicauda. Leach, from brackish water, Trimley Marshes. Leach, in establishing a 

 second species, S. hookeri, at first speaks of it as ' discovered by Mr. W. J. Hooker on the Norfolk 

 coast,' " but later writes, ' Habitat in Suffolcii ad littora maris ; color cinereus aut rufescens, 

 punctulis nigris sparsus. Cum copii crustaceorum benignissime communicavit amicus W. J. 

 Hooker, cujus nomen gerit.' '* It is tantalizing to think of the light which might have been thrown 

 on the carcinology of this county by the families of Dawson Turner, James de Carle Sowerby, 

 and William Jackson Hooker, had not their passing interest in it been diverted to other branches of 

 natural history. As to the two species it is no longer quite certain that they ought to be retained 

 in the genus Sphaeroma^ and it is a little uncertain whether they should be specifically separated one 

 from the other. In the same tribe the family Limnoriidae contains the widely distributed gribble, 

 which Leach in 1814 called Limnoria terebrans. He says of it, 'This new and highly interesting 

 species was sent to Dr. Leach by Mr. Stevenson, from the Bell Rock, in logs of wood, which it 

 perforated in the most alarming manner. He has since received it from the coast of Suffolk.'" 

 Kirby and Spence in their Introduction to Entomology, published in 181 5, had already paid much 

 attention to injurious insects, but without any notice of the gribble. For this, which they evidently 

 considered a serious omission, they endeavoured to atone at great length in an Appendix issued the 

 very next year. Therein it is stated, ' The Linnean order Aptera furnishes another timber-eating 

 insect, a kind of woodlouse (Z,/OTnor/'a terebrans of Dr. Leach), which in point of rapidity of execution 

 seems to surpass all its European brethren, and in many cases may be productive of more serious 

 injury than any of them, since it attacks the woodwork of piers and jetties constructed in salt water, 

 and so effectually as to threaten the rapid destruction of those in which it has established itself In 

 December last I was favoured by Charles Lutwidge, esq., of Hull, with specimens of wood from 

 the piers at Bridlington Quay which woefully confirm the fears entertained of their total ruin by 

 the hosts of these pygmy assailants, that have within a few years made good a lodgement in them, 

 and which, though not so long as a grain of rice, ply their masticatory organs with such assiduity 

 as to have already reduced great part of the woodwork into a state resembling honeycomb.' '''^ 

 Further on the writer says, ' The inhabitants of Bridlington Quay believe that this insect was left 

 there, a few years ago, by an American vessel, with what foundation I know not : but that it is 

 an imported insect, and, like the Teredo navalis, not originally an European animal, seems very 

 probable, from the fact that I can find no description of any species of Oniscus at all resembling it 

 prior to that of Dr. Leach, who seems first to have given it a name [Linn. Trans, xi, 371), and it 

 appears highly improbable that, if it had been an European species, it should not long since have 

 attracted attention and been described.'^' It was rather late in the day for these distinguished 

 entomologists to be treating this creature as an insect. As a matter of fact it had been described 

 in 1799 by J. Rathke as Cymothoa lignorum, the generic name clearly indicating that it was known 

 on the Continent to be a marine crustacean. Three kindred species from various parts of the 

 world have since been described. How and when Limnoria lignorum was first introduced into 

 Great Britain it might not be easy now to ascertain. It is unsafe to argue that it was not 

 living and working among us, because no one had said anything about it till the combined 

 efforts of Robert Stevenson and Dr. Leach made it notorious. 



In the tribe Valvifera the family Astacillidae contains Jstacilla longicornis (Sowerby) of which a 

 specimen dredged off Yarmouth was given me several years ago by Dr. G. S. Brady. In the 

 family Idoteidae Metzger reports Idotea tricuspidata, Desmarest, from Yarmouth Harbour.^^ By 

 this name is probably intended /. halthica (Pallas), which is everywhere common on our coasts. 



" Edinb. Encycl, vii, 433. " Trans. Linn. Soc. (1815), xi, 369. " Editib. Er.cycl. vii, 433. 



'" Op. cit. 17. " Ibid. 19. " Hordicefahrt Pomm. 285. 



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