Beu: Evolution of Janthina and Reduzia 
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8 Reduzia hargravesi Cox (1870: 172, pi. 16, fig. 8); Port 
Stephens, New South Wales; extremely large as well as 
unusually tall and narrow. Holotype in NHMUK. 
9 Reduzia montrouzieri Souverbie (1871: 334; 1872: 57, 
pi. 1, fig. 8); Art I., New Caledonia. Syntypes in MHNB. 
10 LymnaeaJpalmeri Dali (1871: 135; 1925: 25, pi. 17, fig. 
8); delta of the Taqui River, head of the Gulf of California; 
holotype (inUSNM) illustrated by Abbott & Dance (1982: 
70, bottom right fig.) and here (Figs 36E, H). 
11 Reduzia globosa E. A. Smith (1876: 551, pi. 30, fig. 8); 
Tarawa, Gilbert Islands. Holotype in NHMUK. Probably 
a juvenile specimen of R. lutea, but as it is unusually short 
and wide, also possibly an Alexania species, a benthic 
epitoniid. However, the dimensions (Table 12) fall within 
those of other small specimens of R lutea , which are much 
shorter and wider than adults. 
12 Reduzia erythraea Jickeli (1882: 367); Dahlak I., Red 
Sea; illustrated by Thiele (1928: fig. 6). Thiele gave 
no source for his figure, but it is assumed to be of the 
holotype; tall and narrow, resembling the holotype of R. 
hargravesi Cox, 1870 in proportions. Holotype in ZMB. 
13 Reduzia rollandiana var. (3 annamitica Wattebled (1886: 
67, pi. 3, figs 4a-b); Hue, Vietnam; “a considerable 
number of shells of this species was found thrown up on 
the beach of Thuan-an, at the end of a cyclone”. Syntypes 
in MNHN, one illustrated here (Fig. 36K-L). 
14 Recluzia sp.: Murdoch & Suter (1906: 301, pi. 27, figs 
55-56) illustrated a specimen dredged in 200 m off Great 
Barrier Island, NE New Zealand, identified as “ Reduzia 
sp.” Charles Hedley suggested verbally to Murdoch 
and Suter that it was either a larval shell or a new genus 
related to Janthina. It is small (H 3.83, D 3.29 mm), 
trochiform, with almost flat sides, a narrowly rounded 
periphery and a blunt, narrowly rounded apex with no 
distinguishable protoconch, and is essentially smooth. 
Its colour was described as “yellowish-horn, white 
underneath the epidermis” (Murdoch & Suter, 1906:302). 
The specimen, in Suter’s collection in GNS (S3045) is 
a larval shell, probably of Cabestana spengleri (Perry, 
1811) (Ranellidae). 
15 Recluzia effusa [ex Martens ms] Thiele (1928: 78, 
footnote, fig. 2), has a diagnosis and apparently was 
not published elsewhere; from “chinesischen See”. No 
dimensions or illustrations of the shell were provided. 
Thiele (1928: 78, footnote) stated that the shell is not well 
preserved; he published a section through the foregut and 
radula of the presumed type, so it is evidently preserved 
in ethanol, with the shell corroded. The name must be 
attributed to Thiele (1928); assumed to be a synonym of 
R. lutea. Holotype in ZMB. 
16 Recluzia insignis Pilsbry & Lowe (1932: 80, pi. 9, fig. 
3); from Montijo Bay, western Panama; pale brown, 
but with prominent cancellate sculpture, not a Recluzia 
species; tentatively identified as a synonym of the type 
species of Alora, A. gouldii (A. Adams, 1857) by Keen 
(1969; 1971: 436, fig. 669). However, the spire of the 
holotype is markedly taller and narrower and the sculpture 
is considerably more prominent than those of illustrated 
specimens of A. gouldii (Weil etal., 1999: 145, fig. 439); 
possibly a distinct species of Alora or a similar genus; 
benthic Epitoniidae. 
Dimensions and species of Recluzia 
The only character that varies to any obvious extent in 
Recluzia is the spire height, a combined measure of the 
diameter and translation rate of the whorls. To try and 
understand this variation, some of the specimens available 
in AMS, GNS and NMNZ were measured (Tables 12, 13) 
and their height (H), diameter (D) and spire height (SH) 
compared in bivariate plots (Figs 35A-B). Initially this 
resulted in distinguishing two groups of shells, separated 
by spire height. If these are to be recognized as separate 
species, the earliest names for them are R. lutea for the 
more common, shorter, wider species and R. johnii for the 
much less common, taller, narrower one. As Bennett (1840) 
observed a large raft of specimens, he is very much more 
likely to have collected the more common, shorter Recluzia 
species than the rare, taller and narrower species. 
The addition of a greater number of specimens made it 
seem more likely that the two groups intergrade in shape. 
A large lot in NMNZ (Ml55930, Great Exhibition Bay, 
Northland, New Zealand, Mar 1998; 59 specimens, of 
which 43 measured, Table 13) shows that (1) larger shells 
tend to have taller spires than smaller ones; i.e., height 
increases with growth; (2) many of the larger shells have a 
short, wide, shallow flare at the anterior end of the aperture, 
making their dimensions slightly taller and narrower than 
shells without the flare, although the whorls are actually no 
narrower than in specimens without the flare (e.g., see the 
illustration of Recluzia lutea by Habe & Tokioka, 1953: 57, 
fig. 12, identified as R. montrouzieri ); and so (3) specimens 
identified as R. lutea largely intergrade in overall shape with 
specimens identified as R johnii, although the spire outline of 
R johnii is taller and straighter than in R. lutea. The majority 
of specimens in Fig. 35A assigned to R. lutea are included 
in the same field as specimens assigned to R. johnii, and the 
distinction between the two fields is slight. Comparisons of 
the height (H), width (diameter, D) and spire height (SH) of 
a number of specimens (Tables 12, 13) of the two species 
are summarized in Table 11. The overall shape is confirmed 
as similar, the means for H/D being 1.44 for R. lutea and 
1.56 for R. johnii. Contrary to the conclusion about overall 
shape, the quite strongly distinct means of D/SH (1.51 for 
R. lutea, 1.20 for R. johnii ) and the accompanying plot 
comparing diameter with spire height (Fig. 35B) show a clear 
distinction between the shorter-spired species R. lutea and 
the taller-spired species R. johnii. These fields overlap little 
(although the height of the spire was available for only nine 
of the 14 specimens of R. johnii). On average, diameter is 
1.5 times spire height in R. lutea, whereas diameter is only 
slightly greater than spire height (1.2) in R johnii. As seemed 
likely from visual estimation, R johnii is considered here to 
be a rare, second Recluzia species with a taller, narrower and 
Table 11. Summary of dimensions of Recluzia johnii and 
R. lutea (mean, arithmetic mean; SD, standard deviation). 
species H/D D/SH 
range n mean SD range n mean SD 
Reduzia johnii 1.40-1.69 14 1.56 0.119 0.93-1.36 9 1.20 0.185 
Reduzia lutea 1.10-1.73 73 1.44 0.102 1.21-1.95 66 1.51 0.148 
