216 
It is very like C. Archert, Tryon. Man. X., p. 89, t. 33, fig. 
84, 1888, but “ peristome thickened” does not apply, though his 
figure does not portray that character. The species belongs to 
Tasmania. 
Cyelostrema inseriptum, spec. nov. PI. vii., figs. 3 a-b. 
Shell minute, very fragile, discoidal, diaphanous, widely um- 
bilicated. Spire flat, not rising above the plane of the last 
whorl. Whorls four, convex, with a gentle antesutural slope ; 
surface smooth and shining, but incremental striz are visible 
under a pocket-lense. Aperture roundly oval, a little wider than 
high ; peristome incomplete. 
Dimensions of figured example.—Major diameter, 2:2; minor 
diameter, 1:6; height, 1:2 mm. 
Locality.—West coast of South Australia. 
This species differs from the smooth form of C. Zatez by its 
flat spire, the last whorl relatively less high, and by the absence 
of spiral ornament ; it has not the compact build or sunken spire 
of C. charopa. 
Cyclostrema delectabile, spec. nov. Pl. vii, fig. 4. 
Shell small, thin, translucent white, subdiscoidal. Spire 
slightly elevated ; widely and perspectively umbilicated. Proto- 
conch globulose and hyaline. Ordinary whorls three, of rather 
rapid increase ; ornamented by rounded spiral and axial thread- 
lets, which on the antesutural slope are of about equal strength 
and equidistant, producing a reticulation of square meshes ; on 
the rounded periphery the spiral riblets are dominant as far as 
the edge of the umbilical crater, but in its gentle slope the axia 
riblets reappear, and in greater strength than they are posteriorly 
Aperture orbicular ; peristome thin and continuous. 
Dimensions of figured example.—Major diameter, 1:66 ; minor 
diameter, 1:1; height, ‘95 mm. 
Locality.—Fowler Bay, west coast of South Australia; col- 
lected by me in 1879. 
Reticulated sculpture is rare in the family, and the peculiarity 
of its partial development in the present species is in itself a 
sufficiently distinctive character. 
DouBTFUL SPECIES OF CYCLOSTREMA. 
Cyclostrema ecaperatum, spec. nov. PI. vii., figs. 1 a-b. 
Shell small, discoidal ; diaphanous, though somewhat clouded 
around the umbilicus. Spire convex, slightly elevated ; whorls 
four and a-half, inclusive of protoconch of one and a-half smooth 
whorls. The ordinary whorls slightly depressed at the posterior 
suture thence regularly subconvex, suture linear ; all the whorls 
spirally lined, the linear ridges slightly narrower than the inter- 
