434 THE CHICAGO ACADEMY OF SCIENCES. 
SuetL: Elongated, compressed, thin; color spermaceti white, 
sometimes brownish-white; surface shining, marked by heavy, raised 
close-set growth lines which are crossed by fine impressed spiral lines, 
the surface frequently malleated; whorls six or seven, strongly angu- 
lated at the shoulder and flattened on the side, the body whorl much 
contracted, strongly shouldered and flattened in the middle; spire long, 
turreted, tapering; nucleus small, ovate, smooth, resembling jackson- 
ensis in outline; sutures well impressed; aperture long and narrow, 
contracted, in some specimens being almost continuous by the eleva- 
tion of the inner lip; the aperture occupies a little less than half the 
entire length of the shell; outer lip thickened within by a longitudinal 
varix; inner lip rather broad, strongly reflected and appressed to the 
parietal wall and the umbilical region, usually leaving a very small 
chink but frequently entirely closing the perforation; the inner lip is 
tightly appressed at its junction with the parietal wall producing a well- 
marked plait; in some specimens the inner lip emargins the umbilical 
chink, much as in emarginata; axis twisted. 
Length. Width. Aperture length. Width. 
22.00 8.50 10.60 3.75 mill. 
19.25 8.00 9.75 AL Bi) 
16.75 7.50 8.50 Byes 29 
16.50 6.50 9.00 Pia A 
Types: Collection Bryant Walker, No. 11995. 
Type Locatity: Higgins Lake, Michigan. 
ANIMAL, JAW, RapuLa and GeniTaLiA: Unknown. 
RANGE: Michigan. A species of the Canadian region and of the 
Boreal (Canadian) life zone. 
RECORDS. 
MicuicaAn: Higgins Lake, Roscommon Co. (Currier; Walker). 
GroLocicAL RANGE: Unknown. 
Ecotocy: “This species has never been found alive so far as I 
know. It is probably as inhabitant of deep water that only comes to 
shore occasionally and apparently no one as yet has been fortunate 
enough to strike the occasion.” (Walker). 
REMARKS: Contracta is a distinct, easily recognized species, dis- 
tinguished by its long, acute spire, shouldered whorls, compressed body 
whorl and heavily plaited columella. Its very narrow, compressed 
shell and very long and narrow aperture separate it from emarginata, 
to which it is related. It approaches some forms of emarginata can- 
adensis, but is always narrower and thinner. The peculiarly contracted 
aperture, which is sometimes reduced to a mere slit, and its notably 
compressed and shouldered body whorl, are its principal distinctive 
