S. A. X AT., VOL. XV. 
48 . South Just'dlnn: Shells. march 27tii, 1934. 
A. javanicensis Lamarck 1822 ( Fissuretla ) (= F. trapeFina 
.Sowerby 1834: — F. scute!!a Cirav: = F. tasvianiensis Bonnet 
1864: not Palelia scute!! urn Cmelin.. from Cape ol Good Hope). 
PI. 1, fig. 7. Short, quadrate, angles rounded, fissure a little in 
front ol the middle, rather large, elliptical, one fifth the length of 
the shell or a little more; light lawn tint, raved with brown; con¬ 
centric straie fine, regular, more obvious than the radiating ones. 
Length 25, breadth 20, height 7 mm. Uncommon. Beaehport to 
idardwicke 1 >a\, beach and dredged to 24 fathoms Also West¬ 
ern Australia—King George Sound, Lsperance beach, Lamarck 
cave Java as type locality in error. Shells from Guichen Bay, 
South Australia are typical,, so this may be taken as the type 
locality. The outline is unusually square in adult shells (but 
the hall-grown are oval, tile front margin being abruptly truncat¬ 
ed. and strongly arched upward). The posterior end is broadly 
rounded, and also a little curved, upward. Surface sculptured all 
ever with very fine and regular concentric striae, decussated by 
equally fine radiating striae, scarcely visible except near the 
summit. Colour—lawn or cream, with rays and radiating lines 
of light brown. Inside of a rather soiled white, the perforation 
bordered by a strong!' defined callus, which is bounded by a 
roughened tract. Muscle impression very deep, close to the 
edge of the shell, its enlarged anterior extremities connected by 
a roughened scar, ledge of shell blunt. 
A. omicron Crosse K Fischer 1864 (F is surf 11 a ). Oval, de¬ 
pressed; radiating ribs, crossed by line concentric striae, especial¬ 
ly developed towards the summit, and giving that part of the 
shell a granular appearance; intervals between ribs occupied bv 
radiating striae; inside smooth, shining, bluish-white; margin 
simple, acute; fissure oval, bordered white. Length 13, breadth 
K) mm. Rare. Beach—Hardwickc Bay, Denial Bav; dredged 
—Port Lincoln, Investigator Straits. Wool Bav, St. Francis Is¬ 
land, 9-35 fathoms. Also W estern Australia—beach. King George 
Sound, Bunbury, Geraldton. Crosse & Fischer in 1864 gave 
Spencer Gulf as the type locality, and in 1865 altered this to 
‘Gulf St. \ mcent. Colour of shell generally a slate-blue tint, but 
)t may' be yellow, pink, speckled black, or whitish; around the 
perforation it may be white which may run in rays to margin 
at front and back, and sometimes for a little distance down a rib- 
kt at the sides, or articulate several ribs; it may be greyish-white 
dotted with black, or with a few broad reddish radial bands, or 
■he ribs may be white and the interstitial riblets articulated with 
