As requested, here are some moonsnail and egg collar references:
Bouchet, P. and A. Waren. 1993. Revision of the northeast Atlantic bathyl
and abyssal Mesogastropoda. Bollettino Malacologico, Supplemento 3, 577-840.
Giglioli, M.E.C. 1955. The egg masses of the Naticidae (Gastropoda). J.
Fish. Res. Bd. Canada 12:287-327.
Kabat, A.R. 1990. Predatory ecology of naticid gastropods with review of
shell boring predation. Malacologia 32:155-193. 1991. The classification of
the Naticidae (Mollusca:Gastropoda): Review and analysis of the
supraspecific taxa. Bulletin of the Museum of Comparative Zoology
152(7):417-449.
Rick Harbo
Nanaimo,B.C.