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Section Plasiasarepta n. sect. I 



I 



Et^moloff^.- TT^i n(rt-fl(^oL>^-to approach; Sarepta , a genus of pelecyoods,! 

 Shell of me diiim size, well inflated, transversely subellipti- 



cal in outline; inequilateral; innbones low, opisthop-yrate ; areas 

 hefore and behind the beak not differentiated; external sculpture 



consisting of numerous, regular concentric rugae; teeth forning 



the hinge relatively small, in two series, a longer anterior and 

 a shorter, heavier posterior, separated by the ehondrophore ; lig- 

 ament entirely internal, seatel on a relatively lar°-e, deep-set, 

 oblique ehondrophore which is placed immediately before the umbo; 

 internal margin of valve smooth; pallial line not known. 

 Type . - IT. hilli n . sp . 



In ST-rae respects this section is rather far remove:", from the 

 typical IJuculas, especially with regard to outline and sculpture. 

 ATDparently it ap^jroaches the genus Sarepta A. Adams, the tyne of 

 which, 3_. speciosa is a recent Japanese form; the members of that 

 genus are, however, roundei-ovate, and therefore equilateral or 

 subequilateral, and have a narrow, elongated chondrophole, but at 

 the same time there is at least a feeble development of an exteimal ; 

 ligament, j^ the case of £. hilli n. sp. there is no recognizable 

 trace of an external ligament, the ligament being confined to the 

 interior of the shell where it is situated on a i^rominent, oblique- : 

 ly directed ehondrophore. Externally the shell somewhat resembles 



