142 RECORDS OF THE AUSTRALIAN MUSEUM. 



and especially towards tlie base Uecorae evanescent. On the 

 upper whorls radial lamellae predominate and the spirals gradually 

 disappear. Aperture D-shaped, guttered at the anterior angle, 

 whence a serrate crested funicle winds into the umbilicus. 

 Umbilicus sub-cylindrical, deep, narrow, longitudinally striate 

 within by growth lines, overhung by the curled margin of the 

 columella. Length, 53; breadth, 35 mm. 



This is intermediate between the two Australian .species alrea<ly 

 known, being less rough than C. acrdeata, Hedley,-*^ but rougher 

 than C . gracilis, Brazier."^ Appai'ently Ctlielacme, Melvill"-, 

 from the Persian Gulf is also related. 



Hah, — I obtained a few specimens of this species in 17-20 

 fathoms off Masthead Island, Capricorn Group, Queensland. 



Vanikoro sigaretiformis, Potiez and Michaud. 



(Plate xlii., figs. 21, 22). 



Velutina sigaretiformis, Potiez and Micliaud, Galerie Moll. 

 Douai, 1838, p. 508, pi. xxxv., figs. 21, 22. 



Narica sigaretiformis, Recluz, Mag. de Zool., 1845, p. 55, 

 pi. cxxxii., fig. 3. 



The Vanikoro which is commonest in Sydney Harbour appears 

 to me to be V. sigaretiformis, Potiez and Michaud. Mr. E. A. 

 Smith is of the opinion that the V. recluziana, Adams and 

 Angas, described -"^ from Sydney should be united to it. 



In the genus Vanikoro it is frequent that earlier whorls carry 

 comparatively prominent radial ribs, which at a certain stage 

 cease abruptly and are succeeded by un entirely different scheme 

 of delicate spiral threads. Tliese diversely ornamented upper 

 whorls api)ear to afford the most tangil)le features for specific 

 differentiatioii in tliis difiicult group. So sudden and complete is 

 the change that observers have failed to connect the young with 



= Hedley— Proc. Linn. Soc. N. S. Wales, xxv., 1900, p. 89, pi. iii. 

 fig. 10. 



2^ Brazier — Loc. oil., p. 506, pi. xxvi., fig. 13. 



a- Melvill— Proc. Malac. Soc, vi., 1904, p. 54, pi. v., fig. 20. 



23 Adams and Angas — Proc. Zool. Soc , 1863, p. 424. 



