220 POST-TERTIARY ENTOMOSTRACA. 



Distribution. Betent. — Norway, Great Britain, Ireland, Spitzbergen. 

 Fossil. — Scotland : Duntroon, Dumbarton, Cartsdyke, Paisley, Old Mains, Govan, 

 Dalmuir. 



Famihj 6— CYTHERELLID^ ? 

 Genus 1 — Bosquetia, nov. gen. 



Shell dense and thick, the right valve much larger than the left and overlapping both 

 on the dorsal and ventral margins ; valves obliquely ovate, higher in front than behind ; 

 greatest width in the middle ; hinge-joints formed apparently by an overlapping of the 

 dorsal margin of the right valve at each extremity. 



One specimen only of this new genus having occurred to us, we are unable to give 

 its characters with the certainty and minuteness which we could have wished, but an 

 examination of this single example leaves us unable to assign it to any known genus. It 

 differs from the Cypridinadce in the absence of any antennal notch, and from the 

 Cytherellidce in the structure of the hinge-joint, in the general contour of the shell, and 

 probably also in the character of the muscle-spots ; but of this latter point we cannot 

 speak confidently. 



Bosquetia robusta, nov. sp. Plate XII, figs. 18 — 21. 



Carapace, as seen from the side, higher in front than behind ; greatest height equal 

 to nearly three fourths of the length ; anterior extremity broadly rounded ; posterior 

 rounded, somewhat narrowed and prominent in the middle ; superior margin arched, 

 flattened in the middle ; inferior boldly convex, forming with the anterior margin one 

 continuous sweep. Seen from above, ovate, widest near the middle ; width fully equal 

 to half the length, extremities broadly acuminate, tapering more abruptly behind than in 

 front. Surface of the shell perfectly smooth. 

 Length, -^th of an inch. 



Distribution. Fossil. — Scotland: Paisley. 



