8 
Toil Ihkdale. 
^‘mooreuna: \ arious Ceiili'aliiui loiialitios wore confused, and Pilsbry added 
Porrest Biver, North-Western Australia, an indiscreet addition. However 
he figured the speeiinens so that separation is ea.sy. His ili'st measurement of 
his “degerti” is length 2.25, diameter above aperture 1.15 mm., and that 
agrees with his figure 3 on plat(‘ 2, which is here selected as type. His figure 1 
shows a more slender .shell also without locality. 
Mr. E. Sedgwick has sent from Nangeenan via Merredin shells recalling 
this flg’ure 1 in form, lint with the whorls even less rounded and the tip more 
ohtiise. The angular lamella is more pronounced and there is a notable basal 
fold present. The type measures 3 mm. in length by 1.25 mm. in breadth. 
Australbinula helmsiana sp. nov. 
Plate 1. Fig. 2. 
1917 Gastrocopta laraphitii deserti Pilsbry, Man. Concli., (Tryon), Ser. II., 
Yol. XXIY., p. 171, pi. 30, fig. 1, July 18. Specimens only from 
Forrest River, North-Western Australia (R. Helms). 
At the place quoted Pilsbry recorded that these .specimens, one of which 
he figured was “a little larger, 2.5 to 2.55 mm., long, diameter 1.1 mm., or 2.4. 
1.2 mm. There is no brownish tint excejd what may be caused by the dried 
animal. There is a small iiifraparietal nodule in some examples, wuinting in 
others. The eolumellar lanielln has a rounded outline and ascends obliquely 
inward. 1 , 0 wer parietal plica i.s strong, the u|)per smaller and far shorter. 
There is no basal fold. The lip ex]»ands broadly.” Shell minute, cylindrical, 
dextral, whorls round, sutures dee]), spii'e obtuse, sculpture delicate oblique 
striae, mouth with outer li]) exi)anded, aperture with intrusive teeth as noted 
above. 
Australbinula mooreana Smith 1894. 
Plate 1. Fig. 4. 
1894 — Pnpn mooreana Smith, Proe, Malac. Soc. (Loud.), Yol. I., p. 97, 
pi. YII., fig. 25, June. Roebuck Bay, North-West Australia. 
1916 — Bifidarin mooreana Hedley, Journ. Roy. Soc. West Austr., Yol. I, p. 
217, (p. 68 in se))ai'ate). 
1917 — Gastrocopta mooreana Pilsbi'v, Man. Conch. (Tryon). Ser. 2, Yol. 
XXIV. (|)t. 94), p. 16(1, ])!. 30, fig. 4 (copied from Smith): Yol. 
X.KA^I. (pt. 104), p. 230, pi. 24, tig. 6, 7, Nov. 1921: pai'atypieal 
specimens figured, 
“Easily distingnisluHl b.v the .sculpture.’’ 
Striae irregular, interrupted by raalleation or shallow uiu'ven ijitting the 
parietal lamella, is not coiinecled with the aji.gular lamella which is straight, 
the i)arietid not very long an:l only slightly curved. There are only two palatal 
folds, the lower being larger and almost taking the )ilaoe of the basal which 
is missing. The eolumellar lamella is deei)ly set and straight. Pei'hai)s nearer 
fi'CuJnea than Gastrocopta the angular laminae being present hnt not con- 
nected: this feature may he of value in either connection, hence to indicate 
this abnormality the new snhgeneric name Westralcopta is here introduced. 
Pilsbry's account of pnraty])es is here added for reference: “The shell re- 
sembles G. larapinta in contour, but has a special character in the sculpture 
as seen under the microscope, the striae being made irregular, and in places 
interrupted by malleatinn or shallow, uneven pitting, producing sometimes 
a sort of reticulation, not uidike that of some Nesopupae {Tndopupa). The 
