CRUSTACEANS 



They are both devoid of the neck-like constriction which distinguishes head from trunk in 

 Polyphemus. 



As to the Entomostraca taken from Holy Island Lough by Mr. Meek the following 

 explanations are given : ' This gathering was made on 27th June. The pond is a shallow 

 one. The average depth is about 3 feet, and the bottom consists of soft black mud. It is 

 to a large extent overgrown with Equisetum timosum, amongst which the coot and the black- 

 headed gull meet. It gives origin to a small stream which runs close to the village, and 

 was until recently used more or less for domestic purposes. The only fish life obtained was 

 the three-spined stickle-back. . . The gatherings were made by means of a bottom net 

 worked from a canvas boat kindly lent for the purpose by Mr. Newbigin. The proceeds 

 consisted chiefly of Simocephalus vetulus, all the other species, with the exception of Pionocypris 

 vidua, Cyclops viridis, and C. serrulatus, being very poorly represented.' 



The Ostracoda are so completely enclosed between their valves that externally they 

 might be tr.ken for little molluscs rather than crustaceans. The body is seldom segmented, 

 and never carries more than seven definite pairs of appendages. The tribe Myodocopa 

 generally have a heart, which the other tribe, the Podocopa, manage to do without. From 

 the former Brady and Norman report Philomedes brenda (Baird), belonging to the family 

 Cypridinidts, off the coast of Durham, near the Dogger Bank, 1862 (A. M. N.), 1 and in the 

 family Polycopidae Polycope orbicularis, Sars, at ' several points off the coasts of Durham and 

 North Yorkshire.' 8 These are interesting marine species, over which it is impossible to linger, 

 in view of the vast number of species, both freshwater and marine, from the other tribe, 

 which the researches and writings of Brady and Norman have brought to light in connexion 

 with this county. 



In the Podocopa the family Cyprididae supplies the district with Cypria exsculpta (Fischer), 

 found at Seaton Carew ; C. opbtbalmica (Jurine), (N. in litt.) ; C. leev'n (O. F. Muller) and 

 C. serena (Koch), from Holy Island Lough (Meek and Brady), the two latter species, under 

 the more recently accepted name Cyc/ocypris, being reported also from Durham proper (N. in 

 litt.) ; Cypris fuscata, Jurine (N. in litt.) ; C. incongruens, Ramdohr (transferred to Cyprinotus 

 by Sars),* Rainton and Seaton Carew ; C. pubera, O. F. Muller, freshwater pond on Seaton 

 Marsh ; C. v'trens (Jurine), between the typical shape of which and the variety ventricosa ' an 

 intermediate form has been found by A. M. N. at Lumley Dene ; C. elliptica, Baird, ' found in 

 a pond in Foxton Lane, Sedgefield, co. Durham (A. M. N.) ' ; C. reticulata, Zaddach, at 

 Foxton, near Sedgefield ; C. ornata, O. F. Muller, ' the only known British specimens of this 

 species were taken in a pond at Shotton Hall, co. Durham, in May, 1855 (G. S. B.) ' ; Cypri- 

 notus salinus (Brady), originally established as Cypris sa/ina, of which Brady says, ' I first met 

 with C. salina in a cooling pond at Monkwearmouth Colliery, where it lives in great numbers 

 together with Cypridopsis acu/eata, Cypris reptans, and other species, in water which often 

 reaches a temperature of 100 Fahr., and is so impregnated with earthy salts as to deposit 

 a thick coating of carbonate of lime on the leaves of the plants which it supports'; 6 

 Erpetocypris reptans (Baird), the species just mentioned as Cypris reptans ; E. strigata (O. F. 

 Mailer), ' stream in Fulwell Cemetery, Sunderland (G. S. B.) ' ; E. tumefacta (Brady and 

 Robertson), ' near Sunderland (G. S. B.) ' ; Ilyodromus olivaceus (Brady and Norman) (N. in 

 litt.) ; 6 Prionocypris serrata (Norman) 7 (N. in litt.) ; Pionocypris vidua (O. F. Mailer), Holy 

 Island (Meek and Brady), Durham proper (N. in litt.) ; P. obesa (Brady and Robertson) (N. 

 in litt.) ; Cypridopsis aculeata (Lilljeborg), Cowpen Marshes (A. M. N. 1868), Monkwearmouth 

 Colliery, and very 'abundant at Monkton Paper Mills, co. Durham (G. S. B.) ' ; C. villosa 

 (Jurine), found by Brady ' in ponds at Silkswell and Fulwell, near Sunderland ' ; 8 Pota- 

 mocypris fuha, Brady, ' at Fulwell Cemetery, Sunderland ' ; Notodromas monachus (O. F. Muller), 

 many places in Durham ; 9 Candona Candida (O. F. Muller), of which ' the variety claviformis 



1 Trans. R. Dublin Sac., ser. 2, v. 655 (1896). * Loc. cit.,p. 707. 



8 Trans, R. Dublin Soc.,sei. 2, iv. (1889). Monograph of the Podocopa by Brady and Norman. Where no 

 other reference is given the reader is requested to understand that the special localities for the Podocopa 

 are taken from this work. (N. in litt.) signifies that the occurrence of the species in the county of 

 Durham proper is guaranteed by Dr. Norman's manuscript list. 



* Crustacean Fauna of Central Asia, pt. iii, p. 28 (1903). 



6 Trans. Linn. Soc., London, xxvi. 368 (1868). Brady's Monograph of the British Ostracotta. This 

 work will be cited as Man. Brit. Ostrac. 



6 Trans. R. Dublin Sot. ser., 2, v. 724. 7 Loc. cit., p. 725. 



8 Man. Brit. Ostrac., p. 377. Loc. cit., p. 381. 



162 



