- 428 - 



is readily '^ ' ' ' ' ' "" ' . " ' "apressed postci'ior are " ': 

 proc^ :ation of the nar.^-in. lin and v7acca- 



Mav.' i2» ^^'.'".3] 1^ - :-i vonrp.d f *!" ) i "^ier, ^ .: (^on- 



(1). loG. cit., pp. 1109-1110, pi. 18, fig-. 21, 1900. 



ver: and broader. 3_' i^^'"rtoni Oonrad (3), rangira "^ '.'.' o~ 



fr). ,. ■ =^. A-pr. r^PoT. -r.fi ITat., p. 110, -1. ^-, -^i-. ir, lO'iP, 

 ("). Jour, Acad. iiat;. Lici., Philadeliohia, vol. 5, o. ^59, pi. 



Gene to .ecent, is more rotij'.de''' and more compresFi: ■" . 



Dall : ^^^rted (-^-^ ^vr,.n ''o-^r _^. -orr^^ .„ _. ':.ari- 



t ic uia ii?ll (u) , a recent dee-iier water variety," . A!' '" -i this 



(■.). In Gupoy and Jail, Proc. U. .,, ....... .._,...., ,.1. 19, -o. "'^V, 



1896; loe. cit., pp. 1110-1111, 1900. 



(5). Bull. ::iiS. Oom"Dt. Zool. Harvard, Vv-L,. :^-., -i.. 270-271, 



1S85; Bull. U.'S. 7ish Oomm., vol. PO, ^t . 1, "o. l-Pg, -.1. 

 58, fifr.ll, 1^01. 



smell form is slig-htl;" more compre^.-v. ■ than the t7"pical shallow? 

 v/ater s erratum and with slis-htly hig-her inihones, the principal 

 ■"istinction lies in the pin""?: colouring on the nmho and therefore 

 it seems ha25ardous in l;!-c z-v.^^- of the fossil shells, to attempt 



