

The ! r ienrrhn Nahirnfiyt * 



STUDIES ON AUSTRALIAN CH4ROPIDAC 



Port 4 Convex Gc«&«6 



R»>k C. Kkkshaw 



Shell* which have their apical whorl* con*** in -outline ire placed in the 

 genera di&CUssed. There U a *roui> wilk and out 4 without, apertttral I-amcllac- 



The cho't C of t l*e krni mnves In |.mb.<hl}' -unfortunate, for iru:rr aft.* some 

 tonus referred to in this work J5 "plaualc" which in 1act ate a little convtw 

 in outline- However, sludy oi the fartu reveyls that some of these shells ac* 

 more eletntc in outline that* th? majority. The adjective "convex'* is us-e.d her* 1 

 ouJv lo distinguish these elevated twins Irom those which arc "t-Onca^e" 0», 

 more or In;.;, flattened MciiiI>cts of the family 1 1 'irisiat>inui\ic arc* snmctimea 

 markedly couvcv in CRlUhifi bwt the farm ut the Clwropi/ivt h subtly different 

 and not so elevate as those shells which have developed in a, iy comparison, 

 dry habitat. 



lc b noiieetihte thai iliir nrnbilicus U rather wide, in the series without 

 aprrtural lamellae, whereas it is narrow to irhmtte m the series with this 

 feature, \fo<<ovix iu the orst series, the <rul[iiur<- ftNVrtj to hr> rather holit, 

 while in the sufonitpei torale, dentate, genus, the- sculpture T3 very fine, 



Series t — Aperture noi ttantore 



/Vr't.ttf^ii Iredale I9.V5 : In hi* fascinating study ol Western Australian 

 l.-uid shells Ircdalc (1939). E#Y£ ;i description of this POIUS* lot the l$P$, 

 P tit(nuintzf.t Cox 1 86ft. is a Western Australian shell. Points made were the 

 elevation, wide umbilicus, coarse sculpture, loose coiling of the whorls with 

 <fccp sutures, radially S^ruffC JtpeJE with rho tip smooth, The aperture i; 

 rounded, and very uiiiioim among" the vat ions species, the columella is 

 gfn-jMllv rather straight. Many oi the species are decorated wicb inoie i«r 

 Je*s defined streaks or flames of colour at intervals on the whorls. There is 

 :• whole series of species developed hi Tasmania, some of them having the 

 umbilicus narrower than the western species. In the essay preceding this. 

 growth stages m a Tftsmaman species were described. There h a Victorian 

 specie** F- yailiffi Gabriel which agrees with the Tasiuanian, while /'. takc- 

 seithMitrifiHritt (rahriet 1947 has some rc*e-mhlaiK-f% tliou^h ti lacks the colour 

 tnarktiiRs and the straight columella. 



OUn'il>ution: Western Australia, 7asmania, Victoria- 



SftfAacdin Ire.dalc t?33; These arc fragile shells with smooth nrntor.onch, 

 sdull settlptui'e elevated rihs with radial striae crossed ?>> fatiU spirals i*» 

 their interstices. Comjure<l with Psmtttfzra the rihbinj* is more elevate and 

 wider spaced, while the type, S. tftitwt&fo Mrdlpy 192'1 l»ai blender upright 

 bristles on the major ribs. A similar feature de^cril>ed as "loit£ slender poiiiis" 

 occurs in tltv only other species yet dcscrihvd. $, nvuhttl<i Hedlcy 1899, whielt 

 ts also said to have the spire level 



DurtTihutkm: Mid to northern N<nv South Wales. 



hfuiiufinn liedale 19,19 : These shells, like Feruagera, have a radially striate 

 apex w«h the tip .smooth. The adult saiipture consists 0$ strong, distant 

 radial rihs, with close radial striae in the mtersuivs ; the whorls are !oo*;erv 

 toih'd. the nmlnlteus wde and ravetnons- There is a fCSCmblaivc ,n Pi'iMotH'ta 

 hut the form i:; murr depressed than in thai v-cjjus yy^ ly^ ; s /: r?xtift*r 

 Itedalc 1959, and there is a subspecies, firmatitttt Fredale, which has sculpture 

 of bold ndges- 



Oi^itihiition : Western Ausualia. 



UtiHttctropfi Iredale 1937 ; Iredale renvarked d resemhfattce to DtnJltcrmta 

 *»ul wiuicrul the apertur*! looth. There is a depression near the apertuie on 

 the last whorl, the sculpture being lemftrlced as hold. The type ii K .rwrww- 

 q$sn T.egrand 187t, and Brazier, who provided Le^raud Willi the description. 

 j-einarVed the srulptme as of bold stibrugose stiiae. J.atfr Pelterd referred 



