A Keview of the Land Molli:s<'a of Western Australia. 
69 
group previously known, and are (|uite unlike any other type of Australian 
land iuollu.su. 
The .shell is dejircssed, spire little elevated, whorls a little rounded, last 
whorl rounded, base somewhat llattened, umbilieate, mouth fairly large, 
outer lip a little recurved. 
Tile notable features are tin' texture anil coloration. Th(‘ shell is strong, 
but not as stout as trui' lihaijada, and the' shells are bandeil profusely but not 
in the RJuigadoid style. In the type the bands are broken into bars by 
growth periods, but in the second siiecies the bunds are continuous, twelve to 
sixteen bands being counted on the last w'horl. The columella is reflected, 
leaving the umbilicus exposed in the tyjie but almost concealing' it in the 
second .sirecies. 
Exiligada negriensis sp. nov. 
Ihate V., tig. 4. 
Shell subdiscoidal, large, sjiire a little elevated, whorls little I'ounded, last 
whorl how'ever well rounded at the iieriphery, mouth descending a little, 
aperture obli(|Ue, subcircular, open, onti'r lip reflected a little all round, 
flattened basally, coluimdla slanting, broadly reflected but not obseuriiig the 
umbilicu.s, wdiich is marrow but open, shell rather solid. 
Coloralion iieculiar: wdiitish encirck'd by a number of brown lines in- 
terrupted by growth stages so that the lines ajiiiear as a series of (lashes, the 
lines are practically of the same width and numbin' about a dozen on the last 
whorl, three above the pei'i|)heral one which is no stronger than the others, 
the remainder on the base. Tlie apex is ipiite smooth, and a|)]>arently stopped 
by a varix, the adult whorls being only scul|)tnred by I'ery faint gi'owtb striae 
only. The base is somewhat llattened, ihe umbilical area excavate. 
Breadth 22 mm.; height 11 mm. 
Exiligada qualis sp. nov. 
Plate V., fig-. 2. 
Shell with the spire more elevated than in the preceding species, the 
whorls a little rounded, the sutures impressed, the moulh large, the outei' 
lip a little recurved but not flattened basally. The shell has the same texture 
as the preceding and is surely related, but at first sight it dil'fers as thi' 
coloured bands are mibi'okeu. Tlio ground colour is whitish and the lines 
are more munerous, two about the periphery being much broader than the 
remainder and a brighter led-brown. There are halt a dozen above and 
half a dozen below with even one narrow line between the two broad ones. 
The apex is ajipareiitly smooth but there are microscopic radial stria- 
tions present, the adult shell being very Hnely radially growl li striate through- 
out. 
The columella is a little arcuate and expanded, closing the umbilicus 
save for a chink. 
Breadth 20 mm.; height 14 mm. 
Genus PLECTORHAGADA liedale 19.33. 
1933~Plector]tagada Iredale, Kee. Austr. Mus., Vol. XIX., p. .52, Aug. 2. 
Orthotype Helix plectilis Benson. 
This group has a different facies from Tihugada, the spire being more 
conical, the mouth de,sceudiug more rapidly and being more circular, the 
umbilicus being open thongli hidden by the expansion of the columella, and 
