A HISTORY OF DURHAM 



Diaphanosoma hrachyurum (Lii-vin ; Norman in litt.).' The four following families belong to 

 the second tribe. The Uaphniidas furnish this county with D,ipbnla pule.x [Ac Gccv) from 

 Siiotton (Brady) ; D. oitusa, Kurz, taken by the Rev. Canon Norman at Bishopton (Brady) ; 

 D. hamata, Brady, taken by Norman 'in a pond near the East Gate of Lambton Park' 

 (Brady) ; D. lucustris^ Sars, from Holy Island Lough (Meek and Brady) ; D. rmijpui, Straus, 

 which Brady calls Dactylura magna, remarking as to its occurrence : ' Dr. Norman has found it at 

 Layton Farm, near Sedgefield, co. Durham, and I have myself taken it in a pond at Canal 

 Farm, High Barnes, near Sunderland ' (Brady) ; D. longhplna (O. F. Muller) ; (Norman in 

 litt.) ; Ceriodaphnla quadrangula (O. F. Milller), Holy Island Lough (Meek and Brady) ; 

 C. reticulata (Juritie) ; C pulchella, Sars ; C. hitkaudata (O. F. Muller) ; this and the two 

 preceding from Durham county proper (Norman in litt.) ; Simocephnlus vetulus (O. F. Milller), 

 Holy Island Lough (Meek and Brady), and from Durham proper (Norman in litt.) under the 

 new name Simosa vetu/a, recently substituted by Norman, Simocephalus being preoccupied. 

 The Bosminidas are represented hy Bosmina longirostris (O. F. MuUer) ; (Norman in litt.). The 

 Macrotrichidrc comprise Alacrothrix /ff//ta;n/j (Jurine), found 'at Fardingslake, and in the Glebe 

 Engine Pond, Sunderland,' by G. S. B. (Norman and Brady) ; M. hirsuticornis, Norman and Brady, 

 concerning which these authorities say in 1867, ' the only locality at present known for this 

 new species is a slowly running stream at Ashburn, Sunderland, where it was found by G. S. B. 

 in 1864' ; I/yoiryptus sordidus, Lic'vin, for which the same writers report 'two localities in the 

 neighbourhood of Sedgefield, where /. sordldus first occurred in Britain, and was noticed by 

 Mr. Norman.' The Chydoridae are numerously represented, containing Chydorus spharicus 

 (O. F. MoUer) ; Eurycercus lamellatus (O. F. Milller) ; Acroperus harpa, Baird ; all three 

 signalised alike by (Meek and Brady) and by (Norman in litt.) ; Alona tenuicaud'n, Sars, from 

 Sedgefield ; A. costata, Sars, ' found in old colliery pond at Bishop Middleham, and in a pond 

 near Houghton-le-Spring ' ; A. guttata, Sars, ' first found in Great Britain in a small pool at 

 East Herrington,' subsequently ' also in ponds at Marsden ' ; A. teitudinaria (Fischer), since 

 transferred to Graptoleberis, from ' Boldon Flats, Fardingslake, and Hardwicke ' ; Alonopsh 

 ehngata, Sars ; Acroperus nanus, Baird, which has since become Alonella nana (Baird) ; 

 PUuroxus lievis, Sars, ' at " Hell Kettles," near Darlington ' ; P. trigonellus (O. F. Milller), 

 found ' by A. M. N. in Hardwicke Lake and the Forge Dam, near Sedgefield,' and by 

 ' G. S. B. at "Hell Kettles," county of Durham ' ; the foregoing eight species being recorded 

 in 1867 (Norman and Brady), and Alona costata also in 1902 (Meek and Brady). Norman's 

 manuscript list adds Alona quadrangularis (O. F. Milller) ; A. affinh, Leydig ; Pleuroxus aduncus 

 (Jurine) ; P. uncinatus, Baird ; Peracantha truncata (O. F. Moller) ; Leydigia leydig!i,Schud\eT. 

 As a sample of the characters which distinguish these families, it may be mentioned that the 

 first antennas of the female are fixed in the Bosminidae, but movable in the Macrotriehidas ; 

 the five pairs of feet are equally spaced in those two families, but in the Daphniids the fifth 

 pair is remote from the others ; in all the three the second antenna have the dorsal branch or 

 flagellum four-jointed and the ventral one three-jointed, but in the Chydoridse both branches 

 are three-jointed. From the first two families and part of the third the Chydoridse are also 

 separated by the curious characteristic of having a looped intestine. To maintain the extras 

 ordinary activity which some species in this family display, one may surmise that a largg 

 supply of food is needed, and the storage of this within their minute shells may well need an 

 unusual arrangement of the digestive apparatus. 



The Gymnomera are distinguished from the Calyptomera by having the carapace small, 

 not covering the thoracic feet, of which in the tribe Onychopoda there are but four pairs. Its 

 single family, the large-eyed Polyphemids, is represented in the fresh waters of Durham by 

 Polyphemus pcdiculus (Linn.), (Norman in litt.) ; and in the sea by Evadne nordmanni, Lovin, 

 and Pleopis polyphemoides, Leuckart, both reported by Brady from ' Durham coast (ofiF Ryhope), 

 common.'^ For PUopis the generic name now accepted is Lilljeborg's Podon. This has the 

 marsupial part round-ended, as distinguished from Evadne, in which that part is triangular. 



1 To save a confusing repetition of references it may be expedient here to note that ' Norman in litt.' 

 applies to a manuscript list kindly supplied me by Dr. Norman ; localities attested by the name of 

 ' (Brady) ' are from that author's paper ' On the British species of Entomostraca belonging to D.iphnia and 

 other allied genera,' in Nat. Hist. Tram. Northumb., Dm., and Ne^vcastle-upon-Tyne, xlii. (2), 217-248 ; the 

 localities given from ' (Meek and Brady) ' refer to Mr. Meek's Holy Island collection determined by 

 Dr. Brady, in the Report for 1902 of the h'oilkuml/c: land Sea Fisheries Committee, p. 49 (1902); the 

 data referred to '(Norman and Brady)' are from the Nat. Hist. Trans. Northumb. and Dur.,\. 354, etc. 

 (1867). 



*Nat. Hist. Trans. Northumb. and Dur., i. 30 (1867). 



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