THE NAUTILUS. 105) 
general form H. harfordiana Cooper and H. polygyrella 
Binn. & Bld.; rather thin, opaque, lusterless, reddish- 
chestnut colored; surface delicately obliquely striate 
above, smoother beneath, all over beset with short delicate 
hairs. Spire scarcely perceptibly convex, flat; sutures 
moderately impressed ; apex light-colored ; whorls 5}, con- 
vex, very slowly widening, the last wider, rounded on the 
periphery and below; slightly, rather abruptly deflexed 
at the aperture, constricted immediately behind the peristome. 
Aperture oblique, lunate-trilobate ; peristome well expanded, thick- 
ened within, brownish, outer margin bearing a square tubercular 
tooth within, basal margin bearing a small tubercle near its union 
with the outer margin; parietal wall with a long slightly curved 
transverse lamella, its upper termination opposite the superior lip 
tooth. Umbilicus broad and deep. Alt. 5, diam. maj. 8, min. 7 mill. 
Redding, Cal., at the head of the Sacramento Valley. 
Three specimens of this species were found in river drift by Mr. 
E. W. Roper of Revere, Mass. The shell seems to be intermediate 
between HZ. ( Triodopsis) loricata Gld. and H. (Polygyrella) harford- 
tana J. G. Cooper. It differs from the former in being flatter, much 
more broadly umbilicated, with different spire and notably different 
surface sculpture. As to H. harfordiana Cooper there seems to be 
a great deal of confusion in the books; Binney having confounded 
it with a wholly different species from Idaho. It was described and 
ficured in Am. Journ. Conch. v, p. 196, pl. 17, fig. 8. Binney’s 
figure 81, in Manual Am. Land Sh., p. 114, is supposed to represent 
the type specimen, but is in several respects very incorrect. His 
description does not belong to this species at all. The form, in fact, 
belongs with H. polygyrella, differing from that species in the more 
entering, less triangular parietal tooth, absence of internal rows of 
denticles, and presence of small lip-teeth. It is very similar to H. 
polygyrella in form, texture, shape of aperture, and the peristome, 
which is not at all reflected or expanded, but is obtuse, thickened 
within ; in this respect differing from both Triodopsis and Polygyra, 
which have expanded peristomes. Only two specimens of Polygyrella 
harfordiana have been found. H. harfordiana Cooper must not be 
confounded with H. ( Triodopsis) harfordiana W. G. B.; this name 
being preoccupied, Mr. Tryon very properly changed it to H. salmon- 
ensis. 
Academy of Sciences, Apr. 29. 
