416 



MR. G. S. BRADY'S MONOGRAPH OF 



Outline, as seen from below, rhomboidal ; greatest width behind the middle, where the 

 last ventral spine projects, forming a strongly marked angle. 



Length 2^ in. 

 Hab. Shetland {Rev. A. M. Norman). 



One valve only, found amongst dredged sand. 



29. Cttheue dtjnelmensis (Norman). (Plate XXX. figs. 1-12.) 



Cythereis dunelmensis , Norman, Nat. Hist. Trans. Northumb. & Durh. vol. i. p. 23, pi. vii. figs. 1-4. 

 horrida, Sars, loc. cit. p. 45. 



Scandinavian type. Distribution : Recent — Baffin's Bay, Norway, Great Britain. Fossil — Glacial clays 

 and raised beaches, Scotland and Ireland. 



Carapace of female, as seen from the side, elongate quadrangular, highest in front ; 

 greatest height equal to nearly two-thirds of the length. Anterior margin broadly 

 rounded and irregularly fringed with short, blunt spines ; posterior rectangularly trun- 

 cate. Dorsal and ventral margins nearly straight. Outline, as seen from above, sub- 

 ovate, widest in front of the middle, sides nearly parallel ; width equal to about half the 

 length. End view subquadrangular, widest in the middle. Surface coarsely reticulated 

 and excessively rough, with spinous and tubercular elevations ; a curved spinous ridge 

 just within the anterior margin, and a more or less conspicuous tubercle in front of the 

 centre of the valve. The posterior portion of the ventral margin is armed with a series 

 of irregular squamous spines, which often coalesce so as to form a rugged, dentate lamina. 

 The shell of the male (figs. 5-8) is much elongated, height equal to twice the length ; 

 ventral margin distinctly sinuated, and the surface-spines much coarser and stronger. 

 Colour yellowish. " Eyes large and located in the tubercles of the carapace. Upper 

 antennse distinctly six-jointed ; last joint almost equal in length to the two preceding, 

 terminating in four equal setoe. Second joint of the last foot longer than the two 

 following, and bearing on the anterior margin a group of four hairs ; terminal claw very 

 long and slender. Basal portion of the male copulative organs subquadrangular, apical 

 portion subtriangular, produced and obtusely acuminate in front." 



Length in., height ^ in. . rv^... 



Hab. Durham coast, in 40 fathoms {Rev. A. M. Norman) ; off Scarborough {Mr. Leckenby) ; Cumbrae, 

 10 fathoms (Mr. D. Robertson}; Croulin Islands {Mr. J. G. Jeffreys) ; Roundstone [Dr. Alcock). 



This species occurs with tolerable frequency in the Scotch Glacial clays ; but, in the 

 living state, appears to be somewhat rare. In the Erith of Clyde and north-western 

 Scottish coast it is rather more common than on the eastern coast. It seems also to be 

 moderately common on the coast of Norway. . 



30. Cytheue Whiteii, (Baird). (Plate XXX. figs. 21-24.) 



Cythereis Whitei, Baird, Brit. Entom. p. 175, t. xx. figs. 3, 3 a. 



British type. Distribution : Recent — Great Britain, Levant. Fossil — Glacial, Ireland. 



Valves, as seen from the side, elongated quadrangular ; length equal to twice the height. 

 Anterior margin abruptly rounded below, and sloping steeply backwards above, where it 



