Iredale. — Sitter's "Manual of the New Zealand Mollusca." 443 



ally as alike as any of these things are. Thus I would here place Cyclo- 

 strema torridum Hedley (Proc. Linn. Soc. N.S.W., vol. xxxiv, p. 438, pi. 40, 

 figs. 49-51, 1909) ; and I at one time considered C. porcellanum Tate and 

 May would belong here, but examination of specimens in the British 

 .Museum, marked " co-types,'* shows this species to have an oval aperture 

 quite repugnant to my genus, and recalling shells I collected in New Zea- 

 land and which from opercular characters were referred to Laevilitorina. 



Elachorbis gen. nov. 



On j». 153, under Cyclostrema, Suter lias placed his own Cyclostrema 

 eumorpha, and on p. 159. under Circulus, lie has ranged his Cyclostrema 

 subtatei. 



There is a large group of minutiae similar in general characters to Cyclo- 

 strema tatei Angas, and I propose the above genus for these, with that species 

 as type. There cannot be recourse to Cyclostrema, as already pointed out, 

 and Circulus, from examination of the type, would be a bad substitute. 



Melvill has described a whole series of species from the Persian Gulf 

 under the genus-name " Cyclostrema " which would come into this genus. 

 Melvill's idea of " Cyclostrema" as further exemplified in the Trans. Roy. 

 Soc. Edinb., vol. xlviii. L912, pp. 345-46, is about as vague as the Linnean 

 Helix, as he admits "this genus is somewhat multifarious already in its 

 component pa 1 1 s . " " 



Leptothyra imperforata (Suter, 1908). [P. 156.] 



This is where I should place the shell named Pseudoliotia imperforata 

 by Suter. Pseudoliotia Tate, from examination of types, agrees exactly 

 in every detail with Liotia Gray, and must be ranked as an absolute synonym 

 of that name. 



I have not seen Suter's species, but the description and figure agree 

 very closely with the type of Leptothyra, and until the opercular characters 

 are known this should be its generic location. 



When Hedley introduced Liotia latebrosa (Proc. Linn. Soc. N.S.W., 

 vol. xxxii. 1907. p. 493) he commented, "The shell resembles Leptothyra, 

 but the operculum is of a different type. It seems to me probable that 

 neither Leptothyra nor Collonia occurs in Australasian seas, and that the 

 species which have been ascribed to them ought to be transferred to 

 Liotia." This was written before I had shown that Liotia Gray w r as not 

 Liotia Auct., and with our present knowledge it is quite impossible to class 

 Hedley \s Liotia latebrosa with either Liotia Gray (== Pseudoliotia Tate) or 

 Liotina Fischer (= Liotia Auct.). 



Hedley admitted (loc. cit., p. 479) Leptothyra laeta Montrouzor, and 

 this fairly agrees with typical Leptothyra. The species I found at the Ker- 

 madecs and recorded as Leptothyra pie/a Pease is also quite a typical shell. 

 The present species does not closely resemble Cyclostrema mica as A. Adams, 

 but recalls Collonia roseopunctata Ten. -Woods, and this w 7 ould also range 

 under Leptothyra. 



The species Suter includes in Leptothyra (pp. 164-65) are not congeneric, 

 and I will deal with these when I arrive at those pages. 



Brookula corulum (Hutton, 1885). [P. 158.] 



The shell described as Scala corulum by Hutton was temporarily placed 

 under Cyclostrema by Suter and myself in 1908. Suter now ranks it under 



