BY C. HEDLEY. 471 



twenty-five crossbars connected across the ribs by a hooded scale. 

 Prodissoconch with a narrow rim, interior tumid with a central 

 depression. No proper hinge-teeth are developed; their functions 

 are probably discharged by about seventeen strong interlocking 

 pits and tubercles, set without regard to the external sculpture 

 around the broad inner margin of the valve. A wide chondro- 

 phore lies obliquely between a short anterior and a long posterior 

 row of crenulations. Height 1*5 mm.; length 1 54 mm.; depth of 

 conjoined valves 096 mm. 



Numerous examples, both dead and alive, were taken in 17-20 

 fathoms. 



P. scabra resembles P. talei, from which, without a full series, I 

 should not have ventured to separate it. A dense enveloping 

 epidermis conceals the shell of P. tatei in life, but P. scabra is 

 naked. Apart from the epidermis, I rely on the more numerous 

 radials of P. scabra to distinguish it. The northern species is 

 besides smaller, less inflated, more square in outline, and its 

 anterior side less developed. 



Philobrya recapitula, n.sp. 

 (Plate xxxvii., figs. 11, 12, 13.) 

 Shell subquadrate, the anterior side being undeveloped, caus- 

 ing it to be inequilateral, much inflated, solid. Colour white 

 (? bleached). Sculpture: thirty-two concentric furrows traverse 

 about forty-eight radii, of which fifteen are anterior and twelve 

 posterior; on each of the resulting facets is set an elevated bead. 

 The beads are conical, half imbedded on the long axis, the apex 

 directed to the umbo, the base overhanging the furrow. They 

 gradually increase in size to the margin. Prodissoconch large 

 and conspicuous, with two rims set some distance apart; the 

 inner basin is shallow triangular, its centre occupied by a promi- 

 nent spike. Hinge : the ligament set obliquely between two 

 crenulated areas. Under the anterior crenulation a single mas- 

 sive cardinal and socket, below and behind the posterior crenu- 

 lation three laterals. Height 3 mm.; length 1-85 mm.; depth of 

 single valve - 9 mm. 



