48 F 
KKWAN RIVKK 
Ekwan river, portage road at falls; one testiferous specimen, with 
both valves. 
The homologies of the shell of (Jtenodonta are unknown, and it is not 
at all clear which is the anterior and which the posterior side of this 
species. If the .shorter i.s the posterior side, as in Xucula and as 
would seem to be indicated l)y the position of the ligament, then the 
beaks of this species are placed a little bchiiul the midlength and 
vice vnma 
“In outline this shell agrees very neaily with my C'. simulatri.r ai.(I 
less closely with (J. Albertina, Ijut these species had the ligament on 
the longei’, instead of the .shorter end of the hinge.” Ulrich. 
(;.\STKH01>0U.\. 
Pleiirotomaria (or Euomphalopterus ) .sj). indet. 
Ekwan river, upper I'apid : five badly preserved cast.s of the inte- 
rior of the shell of a widely umbilicatod .species of Jieurofomarin or 
£ uompluiloplentg, with a very low obtuse sj>ire. The.se specimens are 
very similar in shape to easts of Pleurotomaria Valeria, Ihlling.s, 
which is probably an Eaomphahplcruit, but the outer whorl of each is 
not so distinctly keeled at the periphery. 
Enomphalopterns, sp. indet. 
Ekwan river, foot 6f portage road : a specimen with the upper 
half of the shell completely worn away, the basal half, whicli is all that 
i.s left, being narrowly iimbilieated and .showing part of a peripheral 
alation. 
Megaloinphala robasta, sp. nov. 
Shell large for the genus, strongly convex but deeply and rather 
widely umbilicated on both sides, the umbilicus occupying about cne 
half of the entire diameter though its margin is not very distinctly 
defined. Whorls at least three and jierhaps more, increa.sing very 
rapidly in .size and laterally expanding, coiled closely on the same 
plane and everywhere in close contact, but with little or scarcely any 
overlapping ; their periphery encircled by a contimiou.s slit-band ; 
exposed portion^ of the inner ones truncated almost vertically but some- 
what obliquely on each side. Outer whorl rounded on the periphery 
in some sp<‘ciinens, faintly and obtusely subangular in others, di.stinctly 
subangular around the umbilical margin on both sides, the umbilical 
wall being steep but somewhat oblique. Slit-band narrow, in half- 
