Abgchantiin 
Gyclostrema pachyston, n. sp. PI. xxix., fig. 10. 
Shell orbicular, depressed, of five whorls, spire slightly 
elevated. First two and a half whorls convex, smooth, fol- 
lowed by a spire-whorl, with five equidistant spiral lire. 
Body-whorl upper surface flatly sloping, nearly smooth, with 
fine curved axial wrinkles antecurrent just below the suture, 
then obliquely retrocedent. Side convex, with four well- 
marked spiral lire to the periphery. Base rounded with 
about eight spiral cords, very flat and low, separated only by 
incisions. | Umbilicus minute, nearly filled up by flat callus 
expansions of the inner lip, producing rude curved radial 
wrinkles. Aperture round; outer lip oblique, thin and 
simple, somewhat crenulated outside by the lire; basal part 
thicker and smooth; inner lip thin where applied to the base 
of the body-whorl, and expanding beyond the concave colu- 
mella as a thick shiny smooth callus to the centre of the per- 
foration. 
Dim.—Greatest diameter, 215 mm.; smallest, 2 mm.; 
height, 1°5 mm. 
Locality.—62 fathoms, north-west of Cape Borda, 10 dead. 
The largest example is 3°2 mm.-in diameter. In the 
larger shells the perforation becomes more open, and its sides 
are radially wrinkled. 
€yclostrema—denselaminatum, n. sp. Pl. xxix., fig. 9, 154 
Shell opaque-white, minute, turbinate, of four whorls, 
nearly detached, rapidly increasing. Protoconch one and 
three-quarter whorls, flatly convex, smooth. Spire-whorls 
convex. Sutures deep. Aperture circular, complete, de- 
tached from the base of the body-whorl; border simple. Um- 
bilicus moderate, perspective. Sculpture begins abruptly 
from the protoconch; valid axial lamin, about as high as 
wide, and one-half or one-third as wide as the interspaces, 
crowded, nearly 50 in the body-whorl, completely encircling 
the whorls and so visible in the umbilicus. Fine hair-like 
spiral threads, about 40 in the body-whorl, less crowded on the 
base and near the suture than on the periphery. 
Dim.—Greatest diameter, 1°55 mm.; smallest, 14 mm.; 
height, 1°1 mm. 
Diagnosis.—Scala nepeanensis, Gatliff. is more elate and 
has fewer axial lamine.  Cyclostrema anyeli, Ten. Woods, is 
more elate and has a smaller perforation. C. johnstont, Bed- 
dome, is similar in shape and has crowded axials, but has no 
spirals. 
Locality.—Type from 62 fathoms, north-west of Cape 
Borda; Backstairs Passage, 22 fathoms, 6 dead. 
