243 
the outer lip is very much thickened and prominently margined ; 
the aperture is but slightly angulated at the junction of the basal 
lip and the columella. 
Dimensions.—Length, 6 ; width, 3 mills; micromorphs range 
to half-size. 
Localities. —Common in shell-sand at Streaky and Fowler 
Bays, collected there by me in 1879; I have also taken it at 
Aldinga Bay in St. Vincent Gulf. 
This species is not a typical Zebinella, its ornamentation being 
limited to punctuate sulci, whilst its expanded and variced 
aperture still further removes it. Nevertheless, there are some 
points of agreement therewith, and the distinctive characters are 
not so trenchant as to justify generic separation. In the absence 
of materia! for comparison, I venture to place it in proximity to 
Rissoina expansa, Deshayes, of the Parisian Eocene, which M. 
Cossmann, 1888, has made the type of a new genus, Diaséictus, 
the original diagnosis of which is as follows :—“ Conica, subulata. 
anfranctis regulariter punctulatis; apertura auriformi et 
expansilabri; labro marginato et reflexo, columella arcuata, 
callosa.” Omitting swbulata (which is rather specific than of 
generic value) every word of the definition seems to be applicable 
to the recent species; if my interpretation be correct, then &. 
punctatissima is another instance of an Eocene group surviving 
in Australian waters. 
SUBGENUS RISSOLINA. 
Rissoina crassa, Angas. 
References.—R. crassa, Angas, P.Z.S., 1871, p. 17, t. 1, £. 16 
Reeve, Conch. Icon., f. 70; Tryon, Man. Conch. IX., t. 55, f. 20 
(copied). 
Tryon refers this species to R. Rissoz, Audouin, inhabiting the 
Red Sea, but his figures of the two incline one toa different 
view. 
Distribution.—The type is from Port Jackson, and South 
Australian examples from my collection were named by the 
author of the species. I have specimens of it from King George 
Sound ; it has been recorded from Victoria, and I have received 
it fom Queensland under the name of RB. ‘ambigua. The South 
Australian occurrences are Holdfast Bay, Aldinga Bay and Salt 
Creek in St. Vincent Gulf, Wauraultie in Spencer Gulf, Streaky 
Bay, and at the Head of the Great Australian Bight. 
Rissoina flexuosa, Gould. 
fteferences.—R. flexuosa, Gould, Otia, p. 144, Reeve, Conch. 
Teon., f. 97 ; Tryon, Man. Conch. IX., p. 380, t. 68, £. 1-2 
Synonyms.—R. turricula, Angas, P.Z.S., 1867, p. 114, t. 13, £. 
