I agree with Andrew that it is Reliquieacava robillardi . There is a paper
by C. Massin in Bulletin de L'Institut Royal des Sciences Naturelles de
Belgique  57:79-90 1987 which names this new genus and has a very thorough
study of this species including large detailed illustrations. Contact me
privately for scans/copies

John


>>I've uploaded these new scans and if you have a moment, I would appreciate
>>receiving your thoughts on the matter.
>>(http://www.manandmollusc.net/mystery_shell_avril_hawaii_Juv.html)
>>
>>I have put your information on the page as to the atys and juvenile shells.
>>The scaphopod I'm still searching for more information
>>
>>Thanks for all your help so far and thanks for any and all other thoughts
>>and opinions from this GREAT list!
>
>Having another look, this time with Kosuge & Suzuki 1985 "Illustrated
>Catalogue of Latiaxis and its Related Groups" and Clover 1982
>"Latiaxis Catalog & Illustrated Checklist of Coralliophilidae Family"
>in front of me,  the more elongate beast appears to be Magilopsis
>robillardi (Lienard 1870) and the more numerous Magilopsis doesn't
>appear to match anything in these publications, though it could
>possibly be Magilopsis. cumingii  (H & A Adams 1863); it does not
>appear to be Coralliobia fimbriata, which has stronger spiral cords
>or heavy ribs and which has a broadly-rounded anterior end.