Beu: Evolution of Janthina and Reduzia 
201 
Recluzia johnii (Holten, 1802) 
Figs 2P, R, 36B, D, I-J 
Helix johnii Holten, 1802: 76 (refers to Chemnitz, 1795:284, 
pi. 210, fig. 2076). 
Reduzia hargravesi Cox, 1870: 172, pi. 16, fig. 8; Angas, 
1877: 190; Try on, 1887: 38, pi. 10, fig. 23; Brazier, 1894: 
536; Hedley, 1907: 481; Iredale, 1910: 71; Iredale, 1929: 
279; Iredale & McMichael, 1962: 49. 
Reduzia johnii (Chemnitz).-Jousseaume, 1872: 205; Tryon, 
1887: 38, pi. 10, fig. 24; Hedley, 1910: 358; Winckworth, 
1943: 148. 
Reduzia erythraea Jickeli, 1882: 367; Tryon, 1887: 39; 
Thiele, 1928: 83, fig. 6. 
Type material. Holten (1802) provided a list of binominal 
names from Martini & Chemnitz’s (1769-1795) famous but 
non-binominal iconography in a catalogue prepared for the 
sale of Chemnitz’s collection (Winckworth, 1943). Part of 
the collection was purchased for Peter the Great and is now 
in the Zoological Institute, Russian Academy of Sciences, 
St Petersburg (Martynov, 2002). Chemnitz’s illustrated shell 
is not in ZMUC (J. Knudsen ZMUC pers. comm. 07 Feb 
1978; AGB personal obs.). The possibility that Chemnitz’s 
(1795: 284, pi. 210, figs 1076-1077) illustrated specimen 
of Helix johnii remains in Chemnitz’s collection in the 
Zoological Institute, St Petersburg, was investigated at the 
writer’s request by B. Sirenko (pers. comm. 07 Sep 2012); 
the illustrated specimen is not present. Chemnitz’s drawing 
shows a cream and pale grey shell with a tall spire, closely 
similar in shape and general appearance to the holotype of 
Reduzia hargravesi (Figs 361-J), although with a still slightly 
taller spire, a shallower suture, and one more teleoconch 
whorl. Jousseaume (1872: 203-206) discussed the identity 
of the specimen, translated Chemnitz’s description and 
discussion into French, referred the specimen to Reduzia , 
and redescribed it carefully. Chemnitz received his specimen 
from “M. John, a missionary ... living in Tranquebar, whom 
I must thank for many conchological riches. Whether it 
inhabits Coromandel, Ceylon, the Nicobar Islands or other 
parts of the East Indies, and whether it is a land, freshwater or 
marine shell he gave not the slightest information” (translation 
from Jousseaume, 1872: 204). The strongly and evenly 
inflated whorl shape, essentially smooth surface, circular 
aperture, faint spiral colour band at the continuation of the 
suture around the last whorl, and narrowly reflected inner 
lip agree with characters of Reduzia johnii of the present 
report. It seems feasible that this is the earliest name for a 
species of Reduzia, despite some early authors referring it to 
terrestrial gastropod groups such as Pupa Draparnaud, 1801 
(i.e., Pupilla Fleming, 1828, Pupillidae; not Pupa Roding, 
1798, Acteonidae) or Cochlogena Ferussac, 1821, Helicidae. 
Ferussac (1821: 57) cited the name as Helix ( Cochlogena ) 
johnii Chemnitz, but added “Habit. Les grandes Indes. Espece 
incertain pour le genre”, whereas Gray (1825: 412) simply 
listed it as Pupa johnii without comment. Smith (1910: 203) 
also doubted that this name referred to a Reduzia species 
because of its description by Chemnitz (1795) as “subkeeled”, 
but this appears to refer only to the colour band around the 
last whorl in Chemnitz’s (1795: pi. 210, fig. 2076-2077) 
drawings; the drawings show no obvious sculpture. Similar 
narrow, irregular colour bands or faint spiral grooves are 
present on many specimens of Reduzia (e.g., Habe & 
Tokioka, 1953: fig. 12). Jousseaume’s note seems to have 
been inspired by a specimen in his collection, in MNHN 
(Figs 36B, D). The name has not been applied to any other 
mollusc during the last century, to the writer’s knowledge, and 
Jousseaume (1872) and Winckworth (1943:148) are followed 
in accepting it as the earliest name for a species of Reduzia. 
Reduzia hargravesi , holotype NHMUK197432, stated 
to be from Miall River, Port Stephens, New South Wales, 
Australia, but corrected by the collector, W. Glover (cited 
by Brazier, 1894: 536) to the beach inside the North Head 
of Port Stephens. It is necessary to remove the name Helix 
johnii from uncertain status and associate it unambiguously 
with this species rather than R. lutea. The name H johnii 
originally was not provided with a type locality. The holotype 
of Reduzia hargravesi , NHMUK197432 (Figs 36I-J) is 
here designated the neotype of Helix johnii Holten, 1802. 
Therefore, the type locality of Helix johnii becomes Port 
Stephens, New South Wales. Thiele (1928: fig. 6) illustrated 
the presumed holotype of Reduzia erythraea , ZMB/Moll- 
112603 (E. Strong, USNM, pers. comm. 20 Sep 2012; not 
seen), from Dahlak Island, Red Sea, showing that this name 
also refers to a tall, narrow specimen of Reduzia johnii. 
Other material examined. Australia: New South Wales : 
Collaroy Beach, Sydney (AMS); Maroubra Beach, 
Sydney (AMS); Middle Harbour, Port Jackson (NMV); 
Port Stephens (two lots, AMS); Port Macquarie (NMV). 
Queensland : Green I. (AMS C9824); Palm Islands (AMS 
C9823); 31-37 m, Masthead I. (AMS C19351a); trawled, 
150-200 m, Swain Reefs (GNS WM17360, 1); King’s 
Beach, Caloundra (NMV); Wreck I., off Yeppoon (AMS); 
Fairfax I., Bunker Group (AMS C69053). 
The only other specimens observed in world museums 
are the holotype of Reduzia hargravesi , listed above, and 
Jousseaume’s specimen in MNHN. A specimen in MNHN 
labelled “Rade de Batavia”, i.e., Jakarta, Indonesia (E. 
Strong, USNM, photograph sent pers. comm. 20 Sep 20012) 
has a tall, narrow spire and possibly belongs in R. johnii, but 
is too incomplete for certain identification. 
Distribution. The tall-spired species Reduzia johnii is 
much rarer than R. lutea. In this study, almost all specimens 
observed are from Queensland and northern New South 
Wales, eastern Australia; none have been observed from 
New Zealand. Living specimens have also been collected on 
northern New South Wales beaches by Riek (2017; Fig. 7). 
However, the type specimens of the synonyms demonstrate 
that R. johnii also occurs in the northern Indian Ocean and 
the Red Sea. It probably occurs throughout the tropical 
Indo-West Pacific province. The writer is not aware of 
records from the Atlantic Ocean or the eastern Pacific, but 
this probably results merely from its rarity. 
Dimensions. See Table 12. 
Diagnosis. Moderately large (H to 39, D to 24 mm), larger 
than Janthina species other than J. janthina and J. globosa, 
taller and narrower than all other neustonic Epitoniidae 
including Reduzia lutea ; mean height: diameter 1.56, mean 
diameter: spire height 1.20. Teleoconch of 6-7 whorls; 
whorls strongly and evenly inflated, of almost circular cross- 
section, narrower than in R. lutea ; suture deeply impressed; 
without obvious sculpture. Aperture almost circular, almost 
all specimens without anterior spout-like expansion. Lays 
smooth, narrow, cylindrical to weakly club-shaped, yellow 
egg capsules on underside of float, as in R. lutea. 
