420 



MR. G. S. BRADY'S MONOGRAPH OF 



margin slightly rounded, and armed below with a series of from six to twelve small 

 spines. The dorsum forms a flattened arch ; ventral margin deeply incurved near the 

 middle. Seen from above, the outline is irregularly lanceolate, sharply mucronate in 

 front, obtusely behind, and mostly asymmetrical, on account of a want of correspondence 

 in the tuberculation of the valves ; greatest width situated at the posterior third, equal 

 to less than half the length. End view somewhat pyramidal, strongly keeled below. 

 The surface of the valves is punctate, and marked near the middle with a deep trans- 

 verse furrow ; the anterior half of each valve bears mostly one, the posterior half two 

 tubercles ; but these are subject to much variation in position and number, scarcely any 

 two shells being precisely alike. Colour dull white or straw-coloured. Upper antennae 

 slender, five-jointed ; last joint linear, equal in length to the preceding ; the third 

 scarcely more than half the length of either of the two following ; second equal to third 

 and fourth united. Terminal claws three, nearly equal in length, curved and setiform ; 

 the fourth joint bears at its apex four setse, about equal in length and strength to the 

 terminal claws, and near the middle two shorter setae. The second and third joints bear 

 each one seta. Terminal claws of the second antennse slender. Peet short and stout ; 

 terminal claws of the first and second pairs stout and strongly curved; those of the 

 third pair slender, subsetiform, and equal in length to the three preceding joints ; second 

 joint equal in length to the two following. Males unknown. 

 Length -/q- in., height gij in. 



Hab. In fresh water. Hardwick Lake and Raby Park, county Durham [Rev. A. M. Norman) ; Fulwell 

 Cemetery, Gibside, and in a mill-stream at Hedworth, county Durham ; East Belsay Lake, Northum- 

 berland, and North Shaws Loch, Selkirkshire (G. S. B.) ; in a pond between Hanwell and Southall, 

 Middlesex [Dr. Baird) ; Glasgow and Paisley Canal [Mr. D. Robertson) . 



2. LiMNiCYTHERE MONSTRIFICA (Normau). (Plate XXIX. figs. 9-12.) 

 Cypris monstrifica, Norman, Ann. & Mag. Nat. Hist. vol. ix. 1862, p. 45, pi. iii. figs. 4, 5. 



Valves, as seen from the side, oblong sub quadrangular, strongly spinous and tuber- 

 culate. Extremities boldly rounded, the anterior bearing on each valve a marginal 

 row of about twelve sharp spines." Dorsal margin straight, angulated at its anterior 

 extremity, whence it slopes gently downwards and backwards. Ventral margin incurved 

 centrally. Seen from above, the outline is compressed, oval, each valve bearing two 

 very large spinous tubercles, and several smaller spines and ridges. End view sub- 

 quadrate, irregularly angulated. The valves are closely punctate, furrowed across the 

 middle ; one strong spinous tubercle on the anterior half, and two on the posterior half 

 of each valve. The posterior portion is also beset with numerous small sharp spines. 

 Animal unknown. 



Length -3-3- in. - 



Hab. Fresh water. In the canal at Fleckney, Leicestershire, August 1856 [Rev. A. M. Norman). 



This species was described by Mr. Norman as a Cypris. It seems, however, to have 

 more affinity with the genus Limnicy there, to which I here refer it. Mr. Norman ob- 

 serves that it made no attempt to swim in the few days during which he kept it alive. 



