124 
Records of the Australian Museum (2017) Vol. 69 
pi. 63; Abbott, 1963; Bennett, 1966; Palazzi, 1979; Pinn, 
1980; Turk, 1982; Turk & Humphreys, 1982; Boone, 1984; 
Colman, 1986; Komatsu, 1991; Thompson, 1991; Ueno 
at al ., 1998; Light, 2003; Rolan & Trigo, 2003; Suzuki & 
Shiga, 2008; Okano & Wada, 2012; Riek, 2017). Gardiner & 
Cooper (1907: 46) described the neustonic fauna cast ashore 
at Diego Garcia Atoll, Chagos Archipelago, Indian Ocean: 
. the shore behind being ... sandy, the latter ... having a 
piled-up ridge at high-tide level over a foot [30 cm] broad, 
formed of dead “Portuguese men-of-war” ( Physalia ) and 
the blue-shelled Ianthina ... Other accounts of the timing 
of standings and other aspects of the neustonic community 
have been provided by David (1965), Bennett (1966: 47), 
Morton & Miller (1968: 472), Bingham and Albertson 
(1972), Cheng (1975), Lalli & Gilmer (1989) and Batson 
(2003: 61). Note, however, that Lalli & Gilmer’s (1989: 
fig. Id) illustration identified as Recluzia actually shows the 
cerithioid Litiopa melanostoma. The record of “Recluzia sp.” 
as the most common gastropod epibiont on rafted pumice 
clasts collected along the east coast of Australia (Bryan et 
al 2012: table 2) also was based on a species of Litiopa , 
probably L. melanostoma (Grove, 2014: fig. 2). 
All seven living species of Janthina and Recluzia 
recognized here (Fig. 2) are more-or-less cosmopolitan 
in tropical and temperate seas, in winter minimum sea 
temperatures down to 10°C. However, Janthina pallida 
Thompson, 1840 has not been collected in New Zealand, 
eastern Australia, or the islands between (Lord Howe, 
Norfolk and Kermadec Islands) and seems to have a more 
limited distribution than the other Janthina species. Recluzia 
johnii also is a rare species recorded so far only from the 
tropical Indo-West Pacific province, and in recent times 
entirely from northeastern Australia. Wall-Palmer et al. 
(2016: fig. 6) presented a revised map of world zooplankton 
biogeographical provinces, based on those recognized by 
Oliver & Irwin (2008). Although these appear logical, they do 
not explain the distribution of such species as J. pallida and 
Recluzia johnii. Janthina pallida is absent from the south¬ 
western Pacific area of the circum-global warm-water region, 
although it occupies most or all of the rest of this region. 
Being larger, neustonic epitoniids presumably do not follow 
the same biogeographical patterns as zooplankton. The five 
Janthina species also vary significantly in their relative 
proportions in the fauna in some areas of the ocean. Savilov 
(1969: 318-403; page numbers refer to the translation) 
recorded numbers of specimens of Janthina species in RV 
Vityaz Pacific plankton samples; he did not report Recluzia 
species, implying that none were caught by RV Vityaz. His 
records make it clear that the details of relative numbers of 
Janthina species in different parts of the ocean are due to the 
limitation of some species to particular water masses, trade 
wind belts and current systems, simply as a result of passive 
drifting influenced by water motion and wind. 
Late Neogene (almost entirely Zanclean, Piacenzian or 
Gelasian) fossils of Janthina are recorded here from Santa 
Maria Island in the Azores, other Atlantic islands (Gran 
Canaria, Madeira, Selvagem Grande), coastal Morocco, 
the mid-Atlantic ridge at 23°N 45°W, Jamaica, Japan, the 
Philippine Islands, New Zealand, southern Australia, and 
dredged offshore from Brazil, indicating that they had 
similarly wide oceanic distributions to most of the living 
Janthina species. Therefore, as was pointed out by Finlay 
(1931), Fleming (1953a), Beu (1979) and Beu & Maxwell 
(1990: 292), speciation within Pliocene Janthina species 
potentially provides a cosmopolitan biostratigraphical 
zonation based on readily identifiable macrofossils 20^10 
mm in diameter. All Janthina species are regarded here as 
cosmopolitan in temperate and tropical seas, with no marked 
biogeographical patterns at present apart from the lack of J. 
pallida in the Southwest Pacific, and fossils are assumed to 
have had the same distribution. 
Material and methods 
The writer has tried for many years to understand the 
evolution and taxonomy of “Janthinidae”. The excellent 
monograph by Laursen (1953) was a start towards this, but 
Laursen did not refer to type specimens, and had a relatively 
narrow focus on Janthina specimens captured during the 
Dana expeditions. Laursen (1953) also did not include 
fossils or Recluzia species, and so did not provide a basis for 
understanding the evolution of neustonic Epitoniidae. The 
potential wide biostratigraphical utility of pelagic, relatively 
large, readily identified fossil Janthina species was also an 
impetus for this research. The writer surveyed all literature 
on neustonic Epitoniidae, fossil and living, and examined 
the reported specimens wherever possible. However, this has 
not proven easy, as the present location of almost all of the 
critical fossil material reported in early works is unknown. 
Nevertheless, all known records of fossils are listed in detail 
below. Collections of Recent Janthina and Recluzia species 
in world museums listed below in “Abbreviations” also were 
examined as fully as possible over many years, when the 
opportunity allowed during visits for other research. These 
collections are very voluminous and records of Recent 
specimens are not listed here, other than generalized records 
of all species in Australia and New Zealand. For Australian 
museums, these lists record data collected many years ago 
(1971), before several of the collections were catalogued. 
They do not include precise locality data, but this seems of 
little significance in view of the cosmopolitan distributions 
of almost all Janthina and Recluzia species; the broader 
distribution is more important than precise details. New 
Zealand records include more details for NMNZ and GNS 
collections. The resulting knowledge of distributions, and 
particularly of ages of fossils, was compiled using as accurate 
data on biostratigraphy as possible, to derive an accurately 
dated evolutionary hypothesis useful for biostratigraphers 
as well as biologists. The time scale followed is that of 
Gradstein et al. (2012). 
Present-day specimens are illustrated in colour in Figure 
2. For all original photographs of fossils the specimens have 
been whitened with magnesium oxide before photography; a 
few photographs of significant unwhitened specimens from 
other sources also have been included. Small specimens were 
illustrated by scanning electron microscopy (SEM) where 
protoconchs were available (an FEI Quanta 450 ESEM in the 
Victoria University of Wellington microscopy unit, formerly 
Industrial Research Ltd., Lower Hutt). The external anatomy 
of living specimens has been clarified by many excellent 
colour photographs taken in aquaria of specimens found alive 
on beaches by Tony Healy (Sydney), Dimitris Poursanidis 
(Heraklion, Crete) and Denis Riek (Brunswick Heads, New 
South Wales) (Figs 4-7). 
