;:i-_< On tj t , genua Pompholyx and Us All* . 



taclea long, filiform ; eyeson a tubercular expansion of the inner 



baa 



italia on the lefl aide. Fool very ahort, bluntly rounded. 



Mantle margin simple, not extending beyond the shell. 



Cuap of oentral tooth bidentate. 



I Lb broad; inner tridentate, outer with more or Leas nume- 



rous notch 



Ova capsules rounded, in a delicate envelope. 



Shell depressed, spiral or diacoidal : dextrah 



Gray figures the lateral jaws of P*corneus. 1 have obtained them 

 from P. lentw : yet, as far as 1 know, they have not been noticed in 

 the smaller s^eeies, although they probably exist, but of extreme deli- 

 cacy, and cartilaginous consistency. 



( 'arnptoceras {terebra). 



Buccal plate ': 



T atacles filiform, blunt. Eyes large, situated between the ten- 



tacL 



italia on the lefl side? Foot shorter than the aperture. 



Mantle margin simple, not extending beyond the shell. The an- 

 terior pari of the head moderately produced. 



Teeth? Ova? 



Shell sinistral, turreted, loosely coiled. 



The only information which we have of this singular form ie 

 the description of Mr. Benson, who places il Dear Ancylvs. 



. [croloxus {lacustfis). 



Buccal plate Btrongly arched, papillose. 'Two lateral accessory 

 ],1;,i, ., n.,t continuous as iii . Vncylus, 



Tentacles distant, stout, cylindrical, pointed; bases expanded ; eyes 

 near the inner gidi . 



I ■ oitalia "ii the rigid side. Pool rounded behind. 



Mini le n imple. 



T« ihV 



(»., diacoidal, covered with a minutely tuberonlose tough 



• avelope. 



