276 MEMOIRS OF THE QUEENSLAND MUSEUM . 
specimens occur up to 40 x 35 x 18 mm. The primary ribs number nine, 
secondary ones intercalating but never numbering many ; anteriorly the species 
is narrowed with three prominent ribs, posteriorly broadening with tour stronger 
ribs, one on each side between these two series being; slightly weaker; the ribs 
are elevated, sharply angular, white; the interspaces marked with black angulate 
patches; the margin is strongly cut by these ribs. Inside the shell is white, the 
edge darker, the spatula pale brown speckled with dark-brown spots, a blue 
tinge often present. The same species appears to occur on New Caledonia, but 
the Philippine Island saccharin a is easily separated by its shape, being seven- 
ribbed, the sides almost parallel. Quoy and Gaijnard s stellans is nearer, but 
it lacks the narrowing of the Australian shell. I am now using Dali’s name 
Collisellina (Amer. Journ. Conch., vol. vi, p. 254, 1871) introduced for this 
group alone as tending to more exactitude in differentiating these difficult 
species. 
Penepatella inquisitor gen. & sp. nov. 
(Plate XXXI, figs. 37, IS.) 
When I proposed Patellmax (Prom Linn. Soe. N.S.W., vol. xlix, pp. 183, 
239, Oct. 24, 1924) with P. srjuamifera Reeve as type, 1 had in view the series 
of tropical shells now to be treated. 1 mentioned the series in the British 
Museum of cretacea Reeve, P. pentagona (Born) Reeve, P. strike) or mis Reeve, 
and P. pica Reeve. The specimens mentioned came from Tahiti, Society Group 
(giga-ntea Lesson), Elizabeth 1, and Palmerston I. Representing these localities 
there are in this Museum many specimens from the Paumotu Islands, widen are 
of course paumotensis Gould (Proc. Bost. Soc. Nat. Hist., ii, 150, 1846) and 
agree well with his figure. Specimens from Samoa agree better with Reeve’s 
pica but lack the colouring. Unfortunately there are not shells from Vanik or o 
to confirm flexuom Quoy and Gaimard, but the figure is sufficient to establish 
it as a member of this series. A very fine species comes from New Caledonia, 
very flattened, with nine very pronounced broad ribs and a rich orange spatula, 
which may he called infra area sp. nov. 
The Queensland shell may be now described thus; — Shell star-shaped, 
flattened, apex submediaii, seven primary ribs, three anterior and four posterior. 
The primary ribs have many intercalating ones, rarely one becoming as important 
as the primary seven, the edge being coarsely denticulate in agreement with the 
ribs. Colour greenish white, sometimes with a few scattered black spots; inside 
shining greenish white, spatula indistinct. Length 33 mm.; breadth 30 mm.; 
height 8 mm. 
A smaller elevated form, which may be called arrccia (Plate XXXI, figs. 
21, 22) is easily separated ; in this the primary ribs have become obsolete at a very 
early age and the edges less crenulatc, the ribs much finer. Length 16 mm.; 
breadth 15 mm.; height 11 min.; largest 24 x 21 x 12 mm. 
This species was found living on clamshells at Michaelmas Cav, North 
Queensland, the depressed larger form on the outside, usually obscured b> 
coralline growth, the taller smaller form inside the shells. ^ The genus is 
geographically separated from Patel fanax, which ranges from New South Wales 
southward to Tasmania, while the genus Penepatella lives on the coral reefs 
of Queensland and the South Pacific Ocean. 
