1 36 LATIEOFUSUS. 



it may be readily distinguished from that genus by the unique, 

 costated protoconch and the columellar plaits. 

 Type. — Fusus funiculosus , Lamarck. 



Latirofusus aciformis, Tate (sp.). 



1888. Fttsus aciformis, Tate, Trans. Eoy. Soc. South Aust. vol. x. p. 139, 



pi. vii. figs. 5a-b. 



1889. Latirofusus aciformis, Cossmann, Ann. Geol. Univ. t. v. p. 1089. 



1893. Latirofusus aciformis, Tate and Dennant, Trans. Eoy. Soc. South 



Aust. vol. svii. pt. 1, p. 219. 



1894. Latirofusus aciformis, Tate, Journ. Eoy. Soc. N.S.W. vol. xxvii. 



p. 171. 



Shell elongate with tapering spire ; protoconch not well preserved 

 in the Museum specimens, but evidently smooth or slightly pointed 

 at the commencement and longitudinally costated anteriorly ; 

 whorls but slightly convex, costate, spiral ridges well pronounced, 

 crossed by irregular lines of growth, and, in the brephic stage, 

 slightly cancellate ; body- whorl inflated, descending sharply in front 

 to join the long anterior canal, spiral ridges very prominent and 

 becoming oblique and undulating on the canal proper ; aperture 

 rounded, contracted in front; outer margin rather thick. Urate 

 within ; inner margin detached from the columella, carrying a small 

 plication anteriorly and another on a slight callosity posteriorly ; 

 canal almost closed. 



The species is variable in regard to its ornamentation, some 

 individuals having hardly a trace of longitudinal costse ; the bolder 

 spiral ridges commonly have a single lineation between them. 

 Compared with L. funiculosus, Lamarck, with which M. Cossmann' 

 thought it might possibly be synonymous, we find that L. aciformis 

 is proportionately narrower and does not possess the latiriform 

 longitudinal costse so characteristic of the Paris Basin shell. The 

 protoconch of the latter is, relatively, much smaller, and the shell 

 as a whole is more solid. 



Dimensions. — Length 30 mm. ; breadth 7"5 mm. ; length of 

 aperture 5 mm.; length of anterior canal 11 mm. 



Form, and Loc. — Eocene : Muddy Creek, Victoria. 



1 Op. supra eit. p. 1089. 



