* Klrshaw, StKiUcj on Australian Chtivoh'uUc — 4 rvir.i. N«t. 



I V«| 73 



to ihe holt! "projecting out of the ribs" in his monograph. Authors have scmie- 

 IsW£8 Iftcfl descriptive terms loosely in the past, adding to the confusion 

 inevitable with such tiny shells. Between the ribs the interstitial sculpture is 

 finely striata, and the umbilicus is c*ecpt»oivalJy wide. Iredale gave the dis- 

 tribution as South Tasmania, but there arc shells from the Btl>C Tier which is 

 in the north-east of the State Gabriel has the species from Victoria. 

 Distribution : Tasmania Victoria. 



Tht'tkt'lflmevxflr fredale 1934: This genus was introducer! tor V* Usar/ipnus 

 PfciJTei* i§6J, a s-hcll which appear* 1o have more affinity with Pacific than 

 Australian forms. U BCWfts a doubtful Qiaropiu, and is very distinctive, the 

 sculpture being of close radial ribs with a strong secondary spiral; the shell 

 is elevate in contour and strotujly keeled. Consideration of this beautiful shell 

 'nay he left to the* experts 



distribution: Lizard Island, N'orrh Queensland 



Series. 2 — Aperture Oentofe 



FiiscU&tfL'utt Irednhr 1937 : Iredale describes a subglobosc form with spirally 

 Itrale prolneonck, adnb srnlpttnre almost reliculate, minute umbilicus, ami 

 outer hjp with two internal lamellae. The type is fi. bitthntjfpn.ut Pettcrd 

 1379. The fine sculpture recalls Ov/Mrr/mm/Vi, a Western Australian genus 

 with a cenVave spire and narrow timbiheua. The protoconch sculpture of 

 spirals combined with the adult sculpture and umbilical features &Ugge&lgd 

 Or(OnuiV(i, Mid to a lesstr degree I'ttfomnuh -»nd these are Victorian and 

 Tasmanian and perhaps allied. 



retribution ; N.W. Tasmania (Mi. Bischoffl- 



n t >nthevr>na Tredalc 1933 : ShcU deoresserl convex, elevate s-pire. aperture 

 dentate; adu'.t sculpture cuars* sharp ribs, interstires with very fine r^nial 

 itrfte, umbilicu* moderately narrow ard deep, the protoconch apparently 

 raJuifly rib he 'h Tin: aperture of this shell can only be described a* tub- 

 quadrate. Tjtir type is D, difpu* tira/ier 1871. which species ha* a small n.- 

 tetual "oblong white callus tooth" near thr base of the aperture, a particularly 

 interesting and distinctive aliell, 



Dislr ibutitfli ; : Tasmania (Mt. Wellington). 



Our has- ohset ved that where the protoconch sculpture h spiral the sub- 

 sequent sculpture- [s generally finr, on the nther hand where the protoconch 

 ha»> radial sculpture, stronger sculpture- tends to dominate the adult. The 

 family a» 3 whole tends toward suorur sculpture compared with related 

 groups, although l.nomid forms exhibit inam similarities- Both spiral and 

 radio) sculpture appear to be ancestral at least in -part. but. the tendency 

 toward .strong ribbing may he a comparatively recent acquisition. Shells afe 

 seen which bavc some interstitial rililets or striae tending to become stronger 

 than others. The genera displaying, *nuintli prolocnnch are variously con- 

 nected wirli the other group*, one at least has very simple .strong sculpture 

 only, other sculpture havinjf vanished if ever present There is a tendency 

 fur some aspectr of both adult and protoconch sculpture W become obsolete, 

 and the strong- radial.* and perhaps smooth protoconch to t Humph. Fine sculp- 

 ture is perhaps a sign of degenerating sculpture, or simply a retention of 

 ancestral sculpture 



Cralopa [refold !94li Tile species C. strottdaisis Coy has alreadv been 

 referred to in pari 2 *>i <he-*-. studies ( 1955 a), when it was observed rljjtf rhr 

 shell differed in torm from the eenus Gyroccchtrx in which Hedley had 

 placed it. It was cmliopaieiJ that <?. Hrvudtrnsis vvoiibj be separated and in 

 fact this had already hern done. Thii species was designated the type of the 

 genus Cralafu ui a work which had not been seen by the writer when pre- 

 vious parts of these, studies were prepared, The essential points of dillereuCe 

 are the nature of the spire which 15 not concave but very slightly raised in the 



