BY C. HEDLEY. 477 



Sculpture: down the centre of the valve runs a parting line where 

 follow arrow-heads, each limb stretching to the margin in a broad 

 crescentic wave. The general effect is that of waves in the wake 

 of a fast moving vessel, which would in this case be steering from 

 the ventral margin to the umbo. The double crescents number 

 about fifteen, commence as an arcuate ridge, successively broaden 

 and meet at a sharper angle, are parted by shallow furrows of 

 equal breadth whose ends undulate the lateral margins. Over 

 ridge and furrow runs undisturbed a regular fine concentric 

 striation. Muscular impressions normal. Ligament sunk almost 

 to the centre of the hinge-plate. Length 6 mm.; heights "4 mm.; 

 breadth of single valve T6mm. 



Hab. — Several specimens, some alive, from 17-20 fathoms. 



Obs. — The remarkable sculpture of this pretty little species 

 readily distinguishes it. Judging from literature, it approaches 

 nearest to Circe cequivoca Chemnitz, but differs by being much 

 smaller, more equilateral, and of bolder sculpture. The latter 

 feature recalls waves spreading in the wake of a vessel. 



Granicorium, gen.nov. 



A genus of the Veneridse, nearest to Lioconcha, which it 

 resembles in shape, solid porcellanous shell and muscular impres- 

 sions: but from which it differs by the absence of anterior lateral 

 teeth, the want of a groove defining the lunule, and by the habit 

 of plastering the exterior with sand. Type G. indutum Hedley. 



Granicorium indutum, n.sp. 



(Plate xxxviii., figs. 26, 27.) 



Shell convex, suborbicular, straight on dorsal margin, angled 

 posteriorly and rounded ventrally. Umbo incurved. Lunule 

 deeply excavate. Except the tip of the umbo, the whole of the 

 outside of the valve is densely covered with sand grains, including 

 broken bits of shells, corals, and foraminifera. These grains are 

 so firmly cemented to the valve that it is difficult to remove them. 

 The fragments increase in size towards the margin, and are 

 arranged to slightly overlap each other like tiles on a roof. 



