A HISTORY OF NOTTINGHAMSHIRE 



Newark-on-Trent, writing under date 6 August, 1903, says: 'It certainly 

 does not occur in the Trent, nor, as I am aware, in any streams in my 

 district, Averham, near Newark. The only place I can recollect where 

 they are to be found, and that is many years ago, was at Shireoaks, near 

 Worksop.' Similarly Mr. Henry V. Machin, of Gateford Hill, Worksop, 

 writing on 15 August, 1903, says: 'We have no specimens of the 

 Astacus fluviatilis nearer than Shireoaks.' At the same time he enclosed 

 an extract from The Worksop Guardian for Friday, 14 August, 1903, in 

 which the anonymous writer agrees with him in using the familiar 

 designation Astacus Jiuviatilis for the species now more correctly known as 

 Potamobius pallipes. Under the heading ' Naturalist Notes by "Observer,"' 

 the following account is given : 



I have been very much interested during the past week in watching the proceedings of a 

 female crayfish (Astacus fuviatilis), which, like many other creatures of a larger growth, has 

 recently acquired a new summer suit, but, unlike the members of the genus homo, the crayfish 

 has not to appeal for outside assistance to aid it in this operation. 



When it becomes apparent that the limits of expansion have been reached with the old suit, 

 it loses its sensibility or practically dies, and the constituents of a new shell are deposited between 

 the body and the old shell. At the appointed time the crayfish simply walks out of its old 

 home, which is left empty, but marvellously perfect even to the extreme tips of the delicate 

 antennae. 



After the operation the creature rests for a time in a perfectly limp and helpless condition, 

 until the new shell gradually hardens, and it is once more able to indulge its ready propensity 

 for bickering and quarrelling with the other members of the tribe. One might also mention the 

 extraordinary ability for parting with claws, which seem to be regarded by the crayfish as 

 appendages to be thrown off on the least provocation. Fortunately, Nature has been kind in 

 this respect ; and the loss of a claw is not a serious matter, as a new one speedily grows in the 

 place of the discarded member. 



As with so many other forms of wild life, Worksop may almost be said to have a monopoly 

 for the county, as I am not aware that the crayfish occurs in any other part. Anyone who has 

 seen a lobster may almost be said to have seen a crayfish, for beyond the fact that the lobster is 

 much larger, and lives in salt water, whilst the crayfish is confined to fresh water, there is 

 practically no structural difference between the two. The female crayfish changes her shell, in 

 the manner described above, once each year ; while the more extravagant male requires two 

 coats in the same period. 



The female carries her eggs (which are laid in November or December) with her until they 

 are hatched, and the young, which appear in May or June, are also carried about for some time 

 by their parent. Being nocturnal in their habits, and resting by day under stones or in holes 

 in the banks, these curious creatures are not often observed, which is perhaps as well for them, 

 seeing that they are not particularly well equipped for offence or defence against larger animals. 

 Eels particularly are said to be amongst their worst enemies. As they do not appear to do any 

 harm, and by feeding upon dead animals or other matter found in thewater.no doubt do a great 

 deal towards keeping it pure, we may be pleased that our local fauna includes such an interesting 

 crustacean as the crayfish, sometimes called, but erroneously, the fresh water crab. 



Upon this agreeably-written notice by a local observer a few com- 

 ments may be permitted. In regard to the distribution of Potamobius 

 pallipes within the county, Professor Carr makes it clear that Worksop has 

 not a monopoly, by supplying the information that the species is ' fairly 

 common in the River Maun and mill-dams at Mansfield.' * The process 

 known as exuviation, ecdysis, moulting, or shedding of the outer sheath 

 of the animal is not peculiar to crayfishes, but a common characteristic 

 of the whole crustacean class. Not only does it extend to the delicate 

 tips of the antenna?, the covering of the eyes, the complicated apparatus 



of the mouth-organs, but actually includes the lining of the stomach, 



\ 



1 Tram. Nott. Nat. Soc. for 1902-3, p. i (1904). 

 I 4 2 



