139 
S.A, NAT., VOL. XIV, 
August 3 1st. 1933. Bv Bernard C. Cotton and F. K. Godfrey. 
of laecal and sexual products is through the smaller end of the 
shell; nervous system consists of symmetrically placed centra!, 
pleural, pedal, visceral, and buccal ganglia. 
Dentalium has been subdivided into a number of subgenera 
based chiefly upon apical characters of the shell. The actual 
value of these apical characters for the purpose of classification, 
and there lore the value of subgenera chiefly based upon them, is 
net altogether assured, but in a genus embracing so many species 
some form of division is useful, even though it be somewhat arti- 
liciai. All}' one character, ii relied upon to distinguish the larger 
groups, answers well enough for a time, but it always seems even- 
tually to invite trouble. The shell characters that may be used 
better in combination for the larger or the smaller groups are: 
'JVpe of sculpture, the form of the tip, the degree of curvature, 
the size and thickness of the shell, the position and form of the 
apical slit. We present our suggestions of subgoneric locations 
for FHndersian species. 
Dentalium Linne 1758, in the restricted sense, does not occur 
in South Australia. I'lio nearest approach arc the species, 
che-verti Sharp 5c Pilsbry, katozvense Brazier, robusHim Brazier, 
dnodecimeostatum Brazier, intercalatum Could, hednalli Pilsbry 
k Sharp, decemcostatiim Brazier, tasmaniensis Tonison-Woods, 
ihetidis fledley, octopleiiron \ erco, trancisense Verco, hemilenron 
Verco: for these we proposc:^ — ■ 
Paradentalium subgeu, nov. with inlercaJalum Gould 1859, 
as r\-pe. White shells with six to fourteen strong ribs at the 
apex, continuing to the aperture or becoming obsolete, the inter- 
vals cither smooth, with several striae, nr a median riblet; apex 
small; and orifice simple without terminal pipe, slit, or notch 
(with very few exceptions where a short slit occurs). 
Laevidentalium Fischer 1895 (Subgenus). A long fissure on 
the convex side in the oostenor portion of the shell; surface 
longitudinally striate. Type— D. ergastinnn Fischer 1882 (At- 
lantic). Mainlv deep water species, of al! temperate and tropical 
seas, distinguished chiefly bv the large size and solidity of the 
shell with numerous longitudinal riblets; apical slit is a frequent 
but not invariabe feature. D. zelandicum Sowerby, belongs here. 
Fissidentalium Co.ssman 1888 (Subgenus). ’ Shell smooth 
or showing growth lines only; slighth" ova) or round section; apex 
simple (as defined by Cossman) or with a shallow broad notch 
on the convex side (as expanded by Pilsbrv k Sharp). Type— 
IX vneertum Deshayes 1826, an Eocene fossil of the Paris Basin. 
The principal subgenerIc character is the wholly sculptureless 
shell which is even smooth on the tip. Here we' locate D. hib~ 
ficatum Sowerby. 
