CRUSTACEANS 



shell, but allow us to distinguish eleven segments, the first, however, being composite, to form 

 what may be called the head, carrying the two pairs of antennae, the mandibles, first and 

 second maxilla:, and the maxillipeds. The next five segments are thoracic, each normally 

 with its pair of appendages, and these are followed by five which bear no appendages, forming 

 the tail, abdomen, or pleon. Still it sometimes happens that the last thoracic segment seems 

 more closely united with the pleon than with the rest of the thorax. Hence Giesbrecht draws 

 a line between the Gymnoplea which have the pleon bare of limbs, and the Podoplea, which 

 have, or, more strictly speaking, seem to have a pair of limbs on the pleon. 



Since it will be impossible here to explain or discuss all the latest changes in classification, 

 and since our knowledge of Durham localities for most of the species about to be mentioned is 

 derived from the Monograph of British Copcpoda which Dr. G. S. Brady wrote for the Ray 

 Society, it will be convenient to follow the arrangement adopted in the volumes of that 

 learned and well-known work. The distribution, however, of the genera into families is based 

 on systematic essays of later date, which still show some variety of opinion among leading 

 experts, and make it clear that new students of the Copepoda will not find their field of 

 research already exhausted. To the family Temoridas are assigned Eurytemora velox (Lilljeborg), 

 recorded by Brady as found ' in salt-marshes at Hylton (county Durham),' with the added 

 remark, 'the few specimens which I have recorded as being taken in the sea at Sunderland, 

 must, I think, be looked upon as waifs and strays ' ; ^ Eu. affinis (Poppe), ' in pools near Hartle- 

 pool Slake, county Durham,' this being, according to Brady, a species apparently very liable to 

 be confused with neighbouring forms.^ The family Diaptomidae includes Diaptomus castor 

 Qurine), from ' ponds at Chester Road, Sunderland ; Shotton and Wardley, county Durham 

 (G. S. B.).' 3 The family Centropagids ofFers Centropages hamatus (Ivilljeborg), of which Brady 

 says that it is not uncommon at the surface in the open sea, adding, ' I have once taken it 

 between tide-marks, amongst Algae in rock-pools, near Ryhope.' * The family ParapontellidjE 

 is represented by Parapontella brevicornis (Lubbock), ' in tide-pools on the Durham coast.' 

 For Misophria pallida, Boeck, ' taken off Hawthorn (Durham coast) on a sandy bottom in a 

 depth of 27 fathoms,' Sars establishes a family Misophriidae in the great group of Arpacti- 

 coida.5 The family Pseudocyclopida; (not to be confused with the iPseudocyclopiida;) has 

 Pscudocyclops crassicornis, Brady, dredged off Seaham Harbour in 20—30 fathoms. The family 

 Cyclopidae is more copiously represented, containing Oithona spinifrons, Boeck, possibly the same 

 as the earlier O. helgolandica, Claus, observed ' in the North Sea off Sunderland * ; Cyclopina 

 Uttoralis, Brady, 'amongst weeds between tide-marks,' Ryhope, and off the Durham coast in 

 depths of 4—45 fathoms ; C (?) ovalis, Brady, 'one specimen only taken off Sunderland in the 

 surface net ' ; Cyclops strenuns, Fischer, ' Seaton Marsh, county Durham ' ; ' C. bicuspidatus, 

 Claus, ' in gatherings from Lambton Park (A. M. N.)' ; 7 C. viridis (Jurine), with C.fuscus and 

 C. alhidus of the same author, reported in Norman's manuscript list ; C. insignis, Claus, ' at 

 Hartlepool, where it occurred in brackish pools near the border of the slake ' ; C. serrulatus, 

 Fischer (N. in litt.) ; C. Jimbriatus, Fischer, ' in gatherings by the Rev. Dr. Norman from 

 Rainton Meadows, county Durham ' ; " C. kaufmanni, Uljanin, a rare species hailing from 

 Turkestan, taken freely by Norman from ' pond in Lambton Park (Durham),' and since found 

 by Brady in Hampshire, not known elsewhere;* C. helleri, Brady, taken at Whitburn, but 

 subsequently regarded with doubt ; i" C. phaleratus, Koch, pond at Gibside ; C. salinus, Brady, 

 'got at Holy Island '; 1' Pterinopsyllus insignis, Brady, the earlier generic t\^me, Lophophorus, 

 being discarded on account of pre-occupation,!^ ' three specimens only of this very distinct and 

 beautiful Copepod occurred in a dredging made by Mr. Robertson and the Rev. A. M. Norman, 

 six miles off the Durham coast, near Hawthorn, on a sandy bottom, and in a depth of 

 27 fathoms." 



1 Nat. Hist. Trans. Northumb., Dur., and Nczvcastk-upon-'Tync, xi. (i), 106 (1891). (For the 

 synonymy of the species the student should compare Sars, Crustacea o/Nonvay, iv. 100. 1903.) 



* Loc. cit., p. 108. * Loc. cit., p. 94. 



* Monograph of the Free and Semi-parasitic Copepoda of the British Islands, by G. Stewardson Rrady, M.D., 

 F.L.S., etc., vol. i. Ray Society (1878). It may be acLcpted that species named and explanatory 

 quotations, without further reference, .ire given on the authority of this work. 



' Crustacea of Norway, v. 4 (1903). " Nat. Hist. Trans. Northumb. etc. xi. (2), 73. 



1 Loc. cit., p. 79. 8 Loc. cit., p. 91. 



* Loc. cit., p. 89. '" Loc. cit., p. 92. 

 '• Nat. Hist. Trans. Northumb. etc., new scr. i. 5 (1903). 



1' Monograph, iii. 23, R.ay Sac. (1880). 



164 



