HISTORY MUSEUM
11 DEC 1996

PRESENTED |
ZOOLOGY LIBRARY

Zoology Series

N)Z
ie
NATURAL

HISTORY
MUSEUM

VOLUME 62 NUMBER2 28 NOVEMBER 1996

The Bulletin of The Natural History Museum (formerly: Bulletin of the British Museum
(Natural History) ), instituted in 1949, is issued in four scientific series, Botany,
Entomology, Geology (incorporating Mineralogy) and Zoology.

The Zoology Series is edited in the Museum’s Department of Zoology

Keeper of Zoology Dr C.R. Curds
Editor of Bulletin: Dr N.R. Merrett
Assistant Editor: Dr B.T. Clarke

Papers in the Bulletin are primarily the results of research carried out on the unique and ever-

growing collections of the Museum, both by the scientific staff and by specialists from elsewhere

who make use of the Museum’s resources. Many of the papers are works of reference that will remain
indispensable for years to come. All papers submitted for publication are subjected to external peer review for
acceptance.

A volume contains about 160 pages, made up by two numbers, published in the Spring and Autumn.
Subscriptions may be placed for one or more of the series on an annual basis. Individual numbers and back
numbers can be purchased and a Bulletin catalogue, by series, is available. Orders and enquiries should be
sent to:

Intercept Ltd.

P.O. Box 716

Andover

Hampshire SP10 1YG
Telephone: (01264) 334748
Fax: (01264) 334058

Claims for non-receipt of issues of the Builetin will be met free of charge if received by the Publisher within 6
months for the UK, and 9 months for the rest of the world.

World List abbreviation: Bull. nat. Hist. Mus. Lond. (Zool.)

© The Natural History Museum, 1996

Zoology Series
ISSN 0968-0470 Vol. 62, No. 2, pp. 71-132

The Natural History Museum
Cromwell Road

London SW7 5BD Issued 28 November 1996

Typeset by Ann Buchan (Typesetters), Middlesex
Printed in Great Britain by Henry Ling Ltd., at the Dorset Press, Dorchester, Dorset

Bull. nat. Hist. Mus. Lond. (Zool.) 62(2): 71-82

Issued 28 November 1996

Indian Ocean echinoderms collected during
the Sindbad Voyage (1980-81): 3. Ophiuroidea

and Echinoidea

ANDREW R.G. PRICE

Ecosystems Analysis and Management Group, Department of Biological Sciences, University of Warwick,

Coventry CV4 7AL, UK

FRANCIS W.E. ROWE

Goldbrook Boarding Kennels, Nuttery Vale, Cross Street, Hoxne, Suffolk 1P21 5BB, UK

SYNOPSIS.

At least 44 ophiuroid and 11 echinoid species are recorded from echinoderm collections made during an

international expedition, the Sindbad Voyage, from Oman to China. Sampling localities include the little known Lakshadweep
(Laccadive), Islands and Pula Wé (Sumatra) from which 71% of the species were recorded. Following the zoogeographic
subdivisions of Clark & Rowe (1971), range extensions are recorded for ten of the ophiuroids: W. India (Amphioplus (Lymanella)
sp.); Sri Lanka (Ophiactis modesta, Ophiarachna robillardi, Ophiodyscrita instratus); Maldives area (Cryptopelta granulifera,
Ophiochaeta hirsuta); and Indonesia / East Indies (Amphiura (Amphiura) dejectoides, Amphiura (Amphiura) micra, Amphioplus
(Amphioplus) stenaspis, Ophiogymna pellicula). In addition to the taxonomic treatment, ecological information for each
echinoderm species (habitat types, depth range) is provided and broadly analysed.

INTRODUCTION

The systematics and distribution of Indian Ocean ophiuroids and
echinoids are treated in detail by Clark & Rowe (1971). Regions for
which limited information is available include the Lakshadweep
(Laccadive) Islands, Sumatra and other parts of SE Asia. Recent
studies including the systematics and zoogeography of ophiuroids
and echinoids for the Lakshadweeps include Nagabhushanam &

_ Rao (1972) and James (1989), the latter yielding many new species

records for both echinoderm classes, which fill in gaps in the
distribution records of Clark & Rowe (1971). Recent work has also
been undertaken in SE Asia, including Indonesia (Aziz, 1981) and
the west coast of Thailand (Bussarawit & Rowe, 1985; Bussarawit,

in prep.).

This paper reports on collections of ophiuroids and echinoids
from these areas and other localities during an international,
transdisciplinary voyage across the Indian Ocean from Oman to
China. The expedition, Sindbad Voyage, was undertaken in 1980-81
aboard a replica of an ancient Arab sailing vessel, ‘Sohar’. In

| addition to a systematic account, the zoogeographic significance of

the results and the ecology of each species are broadly assessed.
Details of the holothurian collections (Price & Reid, 1985) and
asteroid collections (Marsh & Price, 1991) resulting from the expe-
dition have already been published. Details of the crinoids collected
are also being prepared (Marshall & Price, in prep.), and a detailed
analysis of the ecology and biogeography of all five echinoderm
classes will follow.

Address for correspondence: First author

© The Natural History Museum, 1996

MATERIALS AND METHODS

Specimens were collected by one of us (A.R.G.P.) and other expedi-
tion members from localities at Muscat, Oman; Chetlat, Laks-
hadweeps (Laccadives); SW India; SW Sri Lanka; and Pula Wé,
Sumatra. Details of the sampling localities are shown in Figure 1.
Sampling was undertaken principally on coral reefs using scuba. At
each locality details of habitat type and depth range were recorded,
along with the number of individuals of each species. The number of
specimens collected is placed in parenthesis after each station
number in the Material lists for each species.

Material was fixed and preserved using standard methods (Lin-
coln & Shields, 1979). Although several specimens (inadvertently
included with the asteroid collections) had been identified earlier by
L.M. Marsh and a few preliminary identifications were made in the
field by A.R.G.P., specimens were mostly identified by and all
species confirmed by F.W.E.R. who is also responsible for taxo-
nomic comments. The ophiuroid and echinoid collections are
deposited at the Natural History Museum, London, where the
holothurian collection (Price & Reid, 1985) and a representative
collection of the asteroids (Marsh & Price, 1991) have also been
lodged.

Following recent practice (e.g. Sloan, Clark & Taylor, 1979),
systematic references are kept to a minimum by citing major works
when possible (e.g. Clark & Rowe, 1971; Clark & Courtman Stock,
1976; Cherbonnier & Guille, 1978; Rowe & Gates, 1995) from
which the original species descriptions, recent authoritative diag-
noses and taxonomic decisions can be traced. In some instances,
further references are given (e.g. Sloan et al., 1979) to provide
additional systematic or biological information.

HISTORY MUSEl

11 DEC 1996
PRESENTED

72 A.R.G. PRICE AND F.W.E. ROWE

oO
50 E 60 70 80. 90 100

Muscat

OMAN

Chotlats ANDAMANS?$

°

LACCADIVES ©,’ at
i SRI LANKA

NICOBARS*

Tangalla

Om ve
owe 0

MALDIVES -

e
4
1°]

lan

Ug Bau

Fig. 1. (a) Map of northern Indian Ocean showing sampling areas (¢) during Sindbad Voyage, with insert (b) for Pula Wé Sumatra

INDIAN OCEAN ECHINODERMS

RESULTS

Class Ophiuroidea

Family GORGONOCEPHALIDAE

1. Astroboa nuda (Lyman, 1874)

SEE. Clark & Rowe, 1971: 78; 92; Clark & Courtman Stock, 1976:
108; 130; Baker, 1980: 60; Rowe & Gates, 1995: 364.

810504D/3 (1), 810504D/4 (1).

NW Klah, Pula Wé, Sumatra.

Subtidal rock/coral; 13 m.

MATERIAL.
COLLECTION SITES.

HABITAT AND DEPTH.

Family AMPHIURIDAE

2. Amphiura (Amphiura) dejectoides H.L. Clark, 1939

SEE. Clark & Rowe, 1971: 80; 97; Cherbonnier & Guille, 1978:

MATERIAL. 810501E/8 (4); ?810428D/5 (2).

COLLECTION SITES. Ug Tapa Gadja & Ug Seukundo, Pula Wé,

Sumatra.

HABITAT AND DEPTH. Subtidal rock / coral, coral reef; 10 & 15 m.

REMARKS. ‘The specimens from stn 810501E/8 appear to accord
well with the original description (Clark, 1939) of the species and
descriptions in Clark & Rowe (1971) and Cherbonnier & Guille
(1978). The 2 specimens from stn 810428D/S differ in their firmer
disc, with coarser ventral scaling and in having 6 arm spines
proximally instead of fine ventral scaling and 5 proximal arm spines.
They are identified as A. dejectoides with reservation. Clark (in
Clark & Rowe, 1971) suspected Amphiura inhacensis Balinsky may
be conspecific with A. dejectoides H.L. Clark, a conclusion con-
firmed by Cherbonnier & Guille (1978). The records included herein
extend the distribution of this species eastwards across the Indian
Ocean from the Red Sea, East Africa and Madagascar to the Indo-
Malayan region. In the latter region it may prove to be widespread.

3. Amphiura (Amphiura) micra H.L. Clark, 1938

SEE. Clark & Rowe, 1971: 80; 97; Cherbonnier & Guille, 1978:
46; Rowe & Gates, 1995: 350.

MATERIAL. 810423B/2 (1).

COLLECTION SITES. Ug Bau, Pula Wé, Sumatra.

HABITAT AND DEPTH. Coral, coral reef; 10—30 m.

REMARKS. This species is recorded across the tropical coast of
Australia and from Madagascar. Its discovery at Pula Wé suggests a
wider distribution in the Indo-Malayan region for this very small
species.

73
4. Amphiura (Amphichilus) ochroleuca (Brock, 1888)

SEE. Clark & Rowe, 1971: 78; 100; Rowe & Gates, 1995: 344.
810502C/1 (1), 810427B/3 (1).
SE Klah, SE Lho Pria Laot, Pula Wé, Sum-

MATERIAL.

COLLECTION SITES.

atra.
HABITAT AND DEPTH. In sponge and on subtidal rock; 0-10 m.

REMARKS. This species is known from the Indo-Malayan region
and more or less circumscribes the Australian continental coastline
(Rowe & Gates, 1995). Pula Wé appears to be the most westerly
point of its distribution known to date.

5. Amphioplus (Amphioplus) stenapsis H.L. Clark, 1938

SEE. Clark & Rowe, 1971: 78; 101; Rowe & Gates, 1995: 344.
810422B/4 (1).
Nr. Klah / Seukundo, Pula Wé, Sumatra (disc

MATERIAL.

COLLECTION SITES.
only).

HABITAT AND DEPTH. Coral reef, 2—8 m.

REMARKS. Although the single specimen comprises only a com-
plete disc with the bases of 2 arms (6 & 9 segments respectively),
there is little doubt of its identity. This record extends the range of the
species to Pula Wé from its type locality, Darwin, N Australia. The
record of A. stenapsis from Madagascar by Cherbonnier & Guille
(1978) is almost certainly based on a misidentification, judging by
the very small size of the radial shields of their specimens. The
confirmation of this species in the western Indian Ocean therefore
requires confirmation.

6. Amphioplus (Lymanella) sp.

MATERIAL. 810109A/1b (2).

COLLECTION SITES. Beypore, India (west coast).

HABITAT AND DEPTH. Subtidal mud, 9 m.

REMARKS. Only the mouthparts and bases of the arms are avail-
able to identify this taxon, which clearly represents a species of
Amphioplus (Lymanella). The dorsal arm plates are trilobed, sug-
gesting either species A. (L.) andreae (Liitken, 1872) or A. (L.)
laevis (Lyman, 1874) in the key provided by Clark & Rowe (1971:
102). Cherbonnier & Guille (1978) indicate that /Jaevis has a wide
range in the Indian Ocean and Indo-Malay region, whereas Clark &
Rowe (1971) record andreae only from the Malay region. Without
complete specimens it is not possible to determine the species nor
indeed whether andreae and laevis are taxonomically separable.

Family OPHIACTIDAE

7. Ophiactis modesta Brock, 1888

SEE. Clark & Rowe, 1971: 105; Rowe & Gates, 1995: 379.
MATERIAL. 810206A/8 (3).
COLLECTION SITES. Negombo, Sri Lanka.

HABITAT AND DEPTH. Coral/rock; 5 m.

74

REMARKS. The 3 specimens were collected in a batch of 6 from
stn 810206A/8 with 3 specimens of O. savignyi. They run
unequivocably to the species O. modesta in the key provided by
Clark & Rowe (1971: 105) where the relationship with other conge-
ners is discussed by A.M. Clark (notes 25—27, pp. 103-105). Rowe
(in Rowe & Gates, 1995) preferred to follow the views of Clark &
Rowe (1971) regarding recognising the validity of the species O.
modesta, a course also followed herein, rather than accept the
sweeping synonymy of O. savignyi, which includes O. modesta,
given by Cherbonnier & Guille (1978).

8. Ophiactis savignyi (Miller & Troschel, 1842)

SEE. Clark & Rowe, 1971: 82; 103; Clark & Courtman Stock,
1976: 164; Cherbonnier & Guille, 1978: 125; Sloan et al., 1979:
102; Price, 1983: 61; Rowe & Gates, 1995: 380.

MATERIAL. 810206A/3 (5), 810206A/8 (3), 810426A/2 (1),
810501E/1 (1), 810501G/3 (1), 8105011/2 (1), 810502F/4 (2).

COLLECTION SITES. Negombo, Sri Lanka; W Rubiah, Ug
Seukundo, E Klah, Pula Wé, Sumatra.

HABITAT AND DEPTH.
5-14 m.

Sponge, coral/rock, subtidal rock, coral reef;

REMARKS. The specimens identified here are fissiparous and 6-
armed with trilobed dorsal arm plates and proximally 6 arm spines,
according well with the key characters given in Clark & Rowe
(1971).

Family OPHIOTRICHIDAE

9. Gymnolophus obscura (Ljungman, 1867)

SEE. Clark & Rowe, 1971: 82; 117; Rowe & Gates, 1995: 411.
810124A/11 (1), 810125A/2 (1), 810430A/20d (2).

COLLECTION SITES. Ala Gala & Deumba Gala, Galle, Sri Lanka;
Ug Seukundo, Pula Wé, Sumatra.

MATERIAL.

HABITAT AND DEPTH. Coral reef and epizoic on crinoids on subtidal
rock; 8-15 m.
REMARKS. This species is commonly epizoic on comasterid

crinoids, the host species for which have not been identified for the
specimens recorded herein.

10. Ophiothela danae Verrill, 1869

SEE. Clark & Rowe, 1971: 84; 116; Clark & Courtman Stock,
1976: 141; Price, 1983: 63; Rowe & Gates, 1995: 419.

MATERIAL. 810125B/1 (3), 810206A/3/28 (4), 810425F/8 (10+),
810428A/2 (7), 810428A/14 (3), 810501 A/3 (30+), 810501A/4 (1),
810428B/1 (2), 810428D/3c (3), 810501E/9 (15+).

COLLECTION SITES. Ala Galla, Galle & Negombo, Sri Lanka; N.
Udjung Lo Me (NE Sabang Bay), Ug Bau, Ug Seukundo, Ug Tapa
Gadja, Pula Wé, Sumatra

HABITAT AND DEPTH. Epizoic on macroalgae, gorgonian, fire coral
(Millepora sp.) sponge and on holothurians (Thelenota ananas), all
on rock /coral; 2-30 m.

A.R.G. PRICE AND F.W.E. ROWE
11. Ophiothrix exigua Lyman, 1874
SEE. Clark & Rowe, 1971: 84; 110; Cherbonnier & Guille, 1978:
140; Rowe & Gates, 1995: 422.
810206A/8 (5), 810502C/1 (2), 810502E/2 (3).
Negombo, Sri Lanka; E Klah, Pula Wé,

MATERIAL.

COLLECTION SITES.
Sumatra.

HABITAT AND DEPTH.
rock; 5—10 m.

Coral/rock, sponge on coral reef and subtidal

REMARKS. One specimen from stn 810206A/8, both from
810502C/1 and two from 810502E/3 are very juvenile specimens.

12. Ophiothrix savignyi (Miller & Troschel, 1842)

SEE. Clark & Rowe, 1971: 84; 109; Cherbonnier & Guille, 1978:
142; Price, 1983: 65.

MATERIAL. 801114B/I (1).

COLLECTION SITES. Muscat, Oman (1 specimen).

HABITAT AND DEPTH. Coral reef; 2 m.

13. Ophiothrix trilineata Liitken, 1869

SEE. Clark & Rowe, 1971: 84; 111; Clark & Courtman Stock,
1976: 145; Sloan et al, 1978: 103; Rowe & Gates, 1995: 423.

MATERIAL. 810420A/5 (2), 810422B/3 (3), 810426A/2 (1),
810428A/9 (2), 810428C/7 (1), 810428D/3a&b (6&2), 810430A/8
(1), 810430A/18 (1), 810430A/21c (1), 810501D/2 (1), 810501E/2
(3), 810501E/S (1), 810501E/8 (1), 810501E/9 (2), 810501E/11 (1),
810502F/2 (1), 810501F/3 (1), 810501G/1 (2), 810501G/3 (1 & 1
juvenile), 810501G/5 (3), 810502C/2 (1 very juvenile), 810502D/4
(4), 810502E/3 (4 juvenile), 810502F/2 (2 juvenile), 810502G/3 (2
juvenile).

COLLECTION SITES. Klah/E Klah, Nr. Seukundo, Ug Seukundo,
Pula Wé, Sumatra, W Rubiah, Ug Bau, Ug Tapa Gadja, Pula We,
Sumatra.

HABITAT AND DEPTH. Coral reef, soft coral / gorgonian, subtidal
rock, sponge/subtidal rock, sponge; 2-30 m.

REMARKS. The majority of specimens exhibit the characteristic
arm colour pattern of 5 longitudinal lines alternating white and dark
blue. However, a few specimens bear a wide median pale longitudi-
nal line along the arms, and at least one specimen (810501E/2) is
distinctively patterned with cream blotches, the linear pattern being
discernable only near the ends of the arms (see Clark & Rowe, 1971:
111). Next to O. (A.) purpurea, this is the most common ophiuroid
species collected.

14. Ophiothrix (Acanthophiothrix) armata Koehler,
1905

SEE. Clark & Rowe, 1971: 84: 111; Rowe & Gates, 1995: 423.
810422B/4 (15+), 810502F/6 (2).

Klah / Nr. Seukundo, Pula Wé, Sumatra.

MATERIAL.
COLLECTION SITES.
HABITAT AND DEPTH. Coral reef, 2—8 m.

REMARKS. This species is recorded from the Indo-Malay region,
tropical Australian coasts and the South Pacific (Clark & Rowe,

INDIAN OCEAN ECHINODERMS

1971). The present record is the most westerly so far known for the
species.

15. Ophiothrix (Acanthophiothrix) purpurea von
Martens, 1867

SEE. Clark & Rowe, 1971: 86; 112; Cherbonnier & Guille, 1978:
148; Sloan et al., 1978: 103: Rowe & Gates, 1995: 423.

MATERIAL. 810204A/4 (3), 810421A/2 (1), 810421A/9 (1 juve-
nile), 810421B/1 (1), 810422D/3 (2), 810423A/4 (1), 810423B/2
(1), 810425D/2 (1), 80425D/4b (1), 810425F/7 (7), 810425F/8 (1),
810426A/2 (3), 810427A/2 (2), 810428A/2 (2), 810428A/7 (3),
810428A/8 (4), 810428A/9 (2), 810428D/3f (23), 810430A/3 (1),
810430A/21c (6), 810430A/22b (1), 810430A/26 (5), 810501 A/1
(1), 810501A/2 (1 juvenile), 810501A/4 (1 juvenile), 810501A/6
(9), 810S501E/7 (2), 810501E/9 (1), 810501E/14 (1), 810501E/15
(1), 810504B/2 (1).

COLLECTION SITES. SW Kalpitiya, Sri Lanka; Ug Bau, Rubiah, Ug
Seukundo, Ug Tapa Gadja, N Klah, ?N. Udjung Lo Me, NE Sabang
Bay, Pula Wé, Sumatra.

HABITAT AND DEPTH. Coral reef, soft coral, fire coral (Millepora
sp.), subtidal rock/coral (epizoic on soft coral / gorgonian & crinoid,
sponge); 2-30 m.

REMARKS. The most common ophiuroid species collected.

16. Ophiothrix (Acanthophiothrix) spinosissima
Koehler, 1905

SEE. Clark & Rowe, 1971: 86; 112.

810422B/4 (4), 810501G/5 (2), 810502F/6 (1).

Ug Seukundo, Klah / Ug Seukundo, Pula Wé,

MATERIAL.

COLLECTION SITES.
Sumatra.

HABITAT AND DEPTH. Coral reef, 2-8 m.

REMARKS. The specimens run down well to O. (A.) spinossima in
the key provided by Clark & Rowe (1971). However, 2 specimens
from stn 810422B/4 have a single dark line running the length of the
dorsal side of the arms, rather than a series of dark spots.

17. Macrophiothrix aspidota (Miiller & Troschel, 1842)
SEE. Clark, 1968: 285; Clark & Rowe, 1971: 114; Clark &
Courtman Stock, 1976: 137; Hoggett, 1992: 91.

MATERIAL. 810123B/6 (1), 810124A/8 (1), 810206A/6 (1),
810206A/7 (1).

COLLECTION SITES.
Galle, Sri Lanka.

Negombo, Closenburg Point, Galle, Ala Gala,

HABITAT AND DEPTH. Subtidal rock, coral / rock; 5—15 m.

18. Macrophiothrix demessa (Lyman, 1861)

SEE. Clark, 1968: 289; Clark & Rowe, 1971: 82; 114; Hoggett,
1991: 1089; 1992: 117; Rowe & Gates, 1995: 412.

801212B/1 (1), 810424B/4 (2).

COLLECTION SITES. Chetlat, Lakshadweep (Laccadive) Islands;
Seulakoe, Pula Wé, Sumatra.

MATERIAL.

75
HABITAT AND DEPTH. Coral rubble, coral reef; 8 m & 20-30 m.

REMARKS. A.M. Clark (1968) transferred this species to the genus
Macrophiothrix referring Ophiothrix (Amphiophiothrix) H.L. Clark,
1946, of which demessa is type (and only) species to the synonymy
of Macrophiothrix H.L. Clark, 1938.

19. Macrophiothrix elongata (H.L. Clark, 1938)

SEE. Clark, 1968: 291; Clark & Rowe, 1971: 82; 114; Price, 1983:
61; Hoggett, 1992: 125.

801111A/5 (1), 801114A/5 (2), 801114B/2 (1).

COLLECTION SITES.

MATERIAL.
Muscat harbour, Oman.

HABITAT AND DEPTH.
m.

Coral reef, subtidal rock/coral/sand; 0.5—3

20. Macrophiothrix longipeda (Lamarck, 1816)

SEE. Clark, 1968: 300; Clark & Rowe, 1971: 82; 114; Clark &
Courtman Stock, 1976: 139; Hoggett, 1991: 1103; Hogett, 1992:
151; Rowe & Gates, 1995: 413.

801212B/3 (1), 810206A/5 (1), 810430A/24a (1).

COLLECTION SITES. Chetlat, Lakshadweep (Laccadive) Islands;
Negombo, Sri Lanka; Ug Seukundo, Pula Wé, Sumatra.

MATERIAL.

HABITAT AND DEPTH. Coral/rock, coral rubble; 5—10 m.

21. Macrophiothrix lorioli A.M. Clark, 1968

SEE. Clark, 1968: 302; Clark & Rowe, 1971: 82; 115; Hoggett,
1991: 1108; Hoggett, 1992: 161; Rowe & Gates, 1995: 414.
810502D/2 (1), 810502E/1 (1).

E Klah, Pula Wé, Sumatra.

MATERIAL.
COLLECTION SITES.

HABITAT AND DEPTH.
10 m.

Coral reef, coral reef/subtidal rock: 5 &

22. Macrophiothrix nereidina (Lamarck, 1816)

SEE. Clark & Rowe, 1971: 86; 107 (as Ophiothrix (Keystonea)
nereidina); Hoggett, 1992: 228 (as Macrophiothrix); Rowe & Gates,
1995: 426 (as O. (Keystonea) nereidina).

MATERIAL. 810421A/4 (1), 810422B/3 (2), 810430A/20d (1),
810430A/21c (2), 810430A/22b (1), 810501E/6 (1).

COLLECTION SITES. Ug Seukundo, Pula Wé, Sumatra.

HABITAT AND DEPTH. Coral reef, coral / rock; 2-10 m.

REMARKS. The species nereidina (which was placed in the
subgenus Ophiothrix (Keystonea) by A.M. Clark, 1967) is included
herein in the genus Macrophiothrix. Hoggett (1991) stated that “it is
particularly difficult to determine the respective boundaries between
Macrophiothrix H.L. Clark, 1938 and two subgenera of Ophiothrix,
O. (Placophiothrix) H.L. Clark, 1938 and O. (Keystonea) A.M.
Clark, 1967. The differences between these taxa have traditionally
relied principally on arm length, shape of dorsal arm plates, relative
spinular armament of the disc plates including cover of the radial
plates (see A.M. Clark, 1967; Clark & Rowe, 1971). The difficulty
in recognising the supraspecific limits of these taxa is made all the
more obvious by the treatment of the species Macrophiothrix

76

propinqua, placed in the subgenus Keystonea by A.M.Clark (1967),
whilst Devaney (1974) described O. (Placophiothrix) westwardi
which has been considered conspecific with propinqua by Hoggett
(1991). Later, in a far-reaching and critical treatment of Macro-
phiothrix, Hoggett (1992: PhD thesis) commits both the taxa
Placophthiothrix and Keystonea to the synonymy of Macrophio-
thrix, transferring the included species of the former two taxa to the
latter taxon and to whom this move is herein credited.

23. Macrophiothrix propinqua (Lyman, 1861)

SEE. Clark & Rowe, 1971: 86; 107 (as Ophiothrix (Keystonea)
propinqua); Clark, 1980: 537; Hoggett, 1991: 1130; Hoggett, 1992:
204; Rowe & Gates, 1995: 415.

MATERIAL. 810428D/5 (5), 810501C/3 (1 juvenile), 810501D/1
(1 juvenile), 810501E/13 (1), 810501DF/1 (1 juvenile), 810501G/1
(1), 810501G/5 (3), 8105011/2 (2), 810502F/3 (1), 810502G/3 (1).

COLLECTION SITES. Ug Tapa Gadja, Ug Seukundo, E Klah, Pula

Wé, Sumatra.

HABITAT AND DEPTH.
soft coral; 2—20 m.

Subtidal rock/coral, coral rubble, coral reef,

REMARKS. This species was first transferred to the genus
Macrophiothrix H.L. Clark, 1938 by A.M. Clark (1980) from
Ophiothrix (Keystonea) A.M. Clark, 1967.

24. Macrophiothrix variabilis (Duncan, 1887)

SEE. Clark, 1968: 308; Clark & Rowe, 1971: 115; Hoggett, 1991:
1138; Hoggett, 1992: 218; Rowe & Gates, 1995: 416.
810206A/4 (1).

COLLECTION SITES.

MATERIAL.
Negombo, Sri Lanka.

HABITAT AND DEPTH. Coral / rock, 5 m.

25. Macrophiothrix virgata (Lyman, 1861)

SEE. Clark & Rowe, 1971: 86; 113 (as Ophiothrix (Placophio-
thrix) virgata); Hoggett, 1992: 236.

810423D/2 (1).

COLLECTION SITES.

MATERIAL.
Ug Bau, Pula Wé, Sumatra.
HABITAT AND DEPTH. Coral reef; 2—8 m.

REMARKS. See remarks under Macrophiothrix nereidina.

26. Ophiogymna pellicula (Duncan, 1876)

SEE. Clark & Rowe, 1971: 84; 117; Clark & Courtman Stock,
1976; 140 (as O. fulgens); Rowe & Gates, 1995: 417.

810504B/2 (1).

Rubiah, Pula Wé, Sumatra.

MATERIAL.
COLLECTION SITES.

HABITAT AND DEPTH. Soft coral; 10 m.

REMARKS. The single specimen has a d.d. = 2.7 mm, a.l. = c. 20
mm. The disc is mottled cream and pink, and the arms are banded
with wide pink and narrow cream bands. An irregular longitudinal
line of cream spots is evident along the dorsal midline of the arms.
The disc is covered (except for the radial shields) with minute,

A.R.G. PRICE AND F.W.E. ROWE

pointed granules with larger, conical spines interradially towards the
edge of the disc. Clark & Courtman Stock (1976) include
Placophiothrix phrixa H.L. Clark as a synonym of O. fulgens
(Koehler) which in turn is included in the synonymy of O. pellicula
by Rowe (in Rowe & Gates, 1995). The species therefore appears to
to be distributed from the Gulf of Aden to the Indo-Malay region and
the NW coast of Australia in depths of 10-116 m.

27. Ophiopteron elegans Ludwig, 1888

SEE. Clark & Rowe, 1971: 84; 115; Rowe & Gates, 1995: 419.
MATERIAL. 810428D/3e (2), 810428D/5 (8).
COLLECTION SITES. Ug Tapa Gadja, Pula Wé, Sumatra.
HABITAT AND DEPTH. Coral reef, subtidal rock/coral; 15 m.
Family OPHIOCOMIDAE

28. Ophiarthrum pictum Miller & Troschel, 1842

SEE. Clark & Rowe, 1971: 86; 121; Rowe & Gates, 1995: 385.
810502H/1 (1).
E Klah, Pula Wé, Sumatra.

Subtidal rock, 2m.

MATERIAL.
COLLECTION SITES.

HABITAT AND DEPTH.
29. Ophiocomella sexradia (Duncan, 1887)

SEE. Clark & Rowe, 1971: 86; 118; Devaney, 1974: 162;
Cherbonnier & Guille, 1978: 179; Rowe & Gates, 1995: 389.

MATERIAL. 81042D8/3d (1).

COLLECTION SITES. Ug Tapa Gadja, Pula Wé, Sumatra.

HABITAT AND DEPTH. Coral reef; 15 m.

REMARKS. The single specimen from Pula Wé measures d.d. = 3
mm; a.l. = 10+ mm (broken near tip). With the exception that the
uppermost of the 4 arm spines is distinctly longer than the lower
ones, the character separating Ophiomastix sexradiata A.H. Clark
1952 (known only from its type locality: Bikini Atoll, Marshall Is,
SW Pacific) from Ophiocomella sexradia (Duncan)(identified
throughout the Indo-West Pacific region and possibly tropicopolitan)
in Clark & Rowe’s (1971) key, all other skeletal characters of the
present specimen accord with those described as fitting O. sexradia
(note 65, p. 118) by A.M. Clark. Cherbonnier & Guille (1978),
following their study of Malagasy material, concur with the com-
ments expressed by A.M. Clark (in Clark & Rowe, 1971) and
tentatively consider Ophiomastix sexradiata to be conspecific with
Ophiocomella sexradia simultaneously agreeing with A.M. Clark
that the status of the genus Ophiocomella as distinct from Ophio-
coma remains doubtful. Although the present specimen does nothing
to clarify the generic status of Ophiocomella, it does support strongly
the view that the two nominal species are conspecific and confirm
the synonymy proposed by Cherbonnier & Guille (1978).

30. Ophiocoma dentata Miiller & Troschel, 1842

SEE. Devaney, 1970: 13; Clark & Rowe, 1971: 86; 119; Rowe &
Gates, 1995: 386.

MATERIAL. 810502H/2b (1).

INDIAN OCEAN ECHINODERMS

COLLECTION SITES. E Klah, Pula Wé, Sumatra.

HABITAT AND DEPTH. Subtidal rock, 2m.

REMARKS. This single specimen (d.d. c. 11.3 mm, distorted)
exhibits two of the described colour forms for the species. At the
centre of the dorsal surface of the disc is a cream spot (c. 1.1 mm
diameter). This is surrounded by an irregular ring (c. 2.2 mm wide)
which is uniformly dusky/grey with darker spots. The remainder of
the disc dorsally and ventrally is reticulated dusky/grey on a cream
background.

31. Ophiocoma erinaceus Miiller & Troschel, 1842

SEE. Clark & Rowe, 1971: 114;119; Clark & Courtman Stock,
1976: 173; Sloan et al, 1979: 106; Bussarawit & Rowe, 1985: | (as
O. similanensis n. sp.); Rowe & Gates, 1995: 387.

MATERIAL. 801212A/3 (1), 810422B/3 (10), 810427B/1 (1),
810427D/5 (1), 810428C/6 (2 juveniles), 810428E/5 (1 juvenile),
810430A/3 (2), 810501F/1 (1), 810501G/5 (3), 810501G/6 (2),
810501K/1 (2).

COLLECTION SITES. Chetlat, Lakshadweep (Laccadive) Islands;
Ug Seukundo, Ug Bau, Lho Pria Laot, Ug Murung, Ug Tapa Gadja,
Pula Wé, Sumatra.

HABITAT AND DEPTH.
subtidal rock; 2—25 m.

Coral reef, coral conglomerate, coral rubble,

REMARKS. This is the commonest species of Ophiocoma col-
lected. The collection comprises some 26 specimens, ranging in size
from d.d. = 3.6—22.2 mm, which show clearly both colour changes
and development of disc granulation with growth. Juveniles up to
d.d. = c. 5 mm bear no granules and are usually marked radially
across each radial shield with a cream line, as described by Bussarawit
& Rowe (1985) for their new species O. similanensis. By d.d. = 5.7
mm granules are developed at the centre of the disc and along 10
radiating lines to the edge of the disc where an irregular line of
granules is developed around the periphery joining these radiating
lines and thus leaving bare the dorsal interradial and radial portions
of the disc. By d.d. = c. 11 mm granules are developed over the
interradial but not radial regions of the disc, but granules are still not
developed ventrally. By d.d. = 12.5 mm granules cover the whole
surface of the disc except for the radial shields which remain bare,
while granules begin to extend in a wedge shape, on the ventral side
of the disc. This arrangement may remain in specimens up to d.d. =
14 mm but generally from about d.d. = > 13 mm the radial shields
become covered by granules. In specimens up to d.d. = 12.5 mm
some central and peripheral granules may be more prominent by
their slightly more elongate shape, but in larger specimens granules
are more evenly rounded and more or less evenly sized. The cream
colour pattern disappears with increased d.d. and is absent in speci-
mens with d.d. > 11 mm.

It is very clear that Ophiocoma similanensis Bussarawit & Rowe,
1985 is based on juvenile specimens of O. erinaceus, to the syn-
onymy of which O. similanensis is herein committed.

32. Ophiocoma pica Miiller & Troschel

SEE. Devaney, 1970: 25; Clark & Rowe, 1971: 86; 118; Clark &
Courtman Stock, 1976: 173; Sloan et al, 1979: 106; Rowe & Gates,

1995: 387.
MATERIAL. 801212A/3 (1).

COLLECTION SITES. Chetlat, Lakshadweep (Laccadive) islands.

Ty

HABITAT AND DEPTH. Coral reef; 20 m.

33. Ophiocoma pusilla (Brock, 1888)

SEE. Devaney, 1970: 25; Clark & Rowe, 1971: 86; 118; Clark &
Courtman Stock, 1976: 174; Sloan et al, 1979: 106; Rowe & Gates,
1995: 388.

MATERIAL. 810422E/4 (1), 810425C/2 (1), 810430A/2Ic (1),
810501E/3 (1), 810501K/4 (1).

COLLECTION SITES. N Klah island, Sabang Bay, Ug Seukundo,

Pula Wé, Sumatra.

HABITAT AND DEPTH.
2=10im.

Coral/sand, coral conglomerate, coral reef;

REMARKS. The 5 specimens range in size from d.d. = 3—7.5 mm.
The characteristic, enlarged, tissue-covered arm spines (see Clark &
Rowe, 1971) appear on specimens from d.d. > 5 mm.

34. Ophiomastix annulosa (Lamarck, 1816)

SEE. Clark & Rowe, 1971: 86; Rowe & Gates, 1995: 390.
MATERIAL. 810123A/3 (1), 810212A/3 (2), 810213A/4 (1).

COLLECTION SITES. Kakoni rocks, Pigeon Island & Unawatuna,
Galle, Tangalla, Sri Lanka.

HABITAT AND DEPTH.
rock; 3-10 m.

Coral reef, subtidal rock/coral, subtidal

35. Ophiomastix caryophyllata Liitken, 1869

SEE. Clark & Rowe, 1971: 86; 120; Cherbonnier & Guille, 1978:
185; Rowe & Gates, 1995: 390.

810425C/1 (2), 810428C/7 ('/,), 810430A/21b (2).
E Sabang Bay, Ug Bau, Ug Seukundo, Pula

MATERIAL.

COLLECTION SITES.
We, Sumatra

HABITAT AND DEPTH. Coral reef, coral/rock; 3-10 m.

Family OPHIONEREIDAE

36. Ophionereis dubia (Miiller & Troschel, 1842)
SEE. Clark & Rowe, 1971: 122; Clark & Courtman, 1976: 179;
Price, 1983: 67; Rowe & Gates, 1995: 408.
810502D/5 (1).
E Klah, Pula Wé, Sumatra.
Subtidal rock/sand; 10 m.

MATERIAL.
COLLECTION SITES.

HABITAT AND DEPTH.
37. Ophionereis fusca Brock, 1888

SEE. Clark, A.M. 1953: 69; 78; Clark & Rowe, 1971: 88; 122;
Rowe & Gates, 1995: 408.

MATERIAL. 810421B/2 (1).

Nr. Seukundo, Pula Wé, Sumatra.

Subtidal sand; 10—20 m.

COLLECTION SITES.

HABITAT AND DEPTH.

78
Family OPHIODERMATIDAE

38. Cryptopelta granulifera H.L. Clark, 1909

SEE. Clark & Rowe, 1971: 88; 128; Rowe & Gates, 1995: 394.

MATERIAL. 801212B/I1 (1).

COLLECTION SITES. Chetlat, Lakshadweep (Laccadive) Islands.

HABITAT AND DEPTH. Coral rubble; 8 m.

REMARKS. Originally described from Mauritius. Rowe & Gates
(1995) describe the distribution as including tropical Australia, the
Indo-Malayan region and Philippine Islands. The specimen is iden-
tified here from the Laccadive Islands for the first time.

39. Ophiarachna affinis Liitken, 1869

SEE. Clark & Rowe, 1971: 88; 123; Sloan et al., 1979: 111; Rowe
& Gates, 1995: 395.

MATERIAL. 810425C/la,b (1).

COLLECTION SITES. E. Sabang Bay, Pula Wé, Sumatra.

HABITAT AND DEPTH. Coral conglomerate; 3—6 m.

REMARKS. A.M. Clark (in Clark & Rowe, 1971: Note 83, p. 123)
describes in detail colour variation in Ophiarachna affinis and O.
mauritiensis de Loriol, concluding that specific distinction between
the two is difficult to make. In the present specimens with d.d. = 22
mm, the disc is uniformly brownish-grey and the dorsal side of the
arms has a broad longitudinal central dusky band either side of
which is a narrower pale band, the 3 bands being demarcated by 4
irregular, very narrow longitudinal dark bands. This corresponds to
A.M. Clark’s form C colour pattern. If O. affinis and O. mauriti-
ensis are conspecific the species is clearly widely distributed in the
Indo-West Pacific region.

40. Ophiarachna robillardi de Loriol, 1893

SEE. Clark & Rowe, 1971: 88; 123.
810126B/4 (1), 810213A/3 (2).
Galle, Tangalla, Sri Lanka.

MATERIAL.
COLLECTION SITES.
HABITAT AND DEPTH. Coral reef, 3—5 m.

REMARKS. This is a significant extension of range for this species
described from Mauritius. The species is recorded as having 5 arm
spines (H.L. Clark, 1909; size not recorded) but the present 3
specimens have 7—9 arm spines at d.d. = 21.5 mm; 9-10 arm spines
at d.d. 31.5 mm and 10-11 arm spines at d.d. = 36.5 mm.

41. Ophiochaeta hirsuta Liitken, 1869

SEE. Clark & Rowe, 1971: 88; 127; Sloan et al, 1979: 115; Rowe
& Gates, 1995 398.

801212B/1 (1), 810425C/2 (1).

COLLECTION SITES. Chetlat, Lakshadweep (Laccadive) Islands; E.
Sabang Bay, Pula Wé, Sumatra.

Coral rubble, 3—8 m.

MATERIAL.

HABITAT AND DEPTH.

REMARKS. Sloan et al. (1979) concluded that variation in the

A.R.G. PRICE AND F.W.E. ROWE

occurrence of spinelets on the discs of 4 specimens from Aldabra,
western Indian Ocean and 2 specimens from Palau in the western
Pacific Ocean which they examined suggested that Ophiochaeta
boschmai A.H. Clark, 1964 is a synonym of Ophiochaeta hirsuta
Liitken, 1869. They pointed out that Cherbonnier & Guille,1978,
had described a new species, O. crinita, based on a single specimen,
from Madagascar, but did not comment further. In the present
collection the specimen from the Lakshadweep Islands accords with
the description of boschmai in that the disc is granule-covered
dorsally but bears spinelets on its ventral surface. The specimen
from Pula Wé, on the other hand, accords with the description of
crinita in that the disc is covered dorsally and ventrally by elongate
spines. Considering the comments by Sloan ef al. (1979), the two
specimens reported herein are referrred to O. hirsuta, with the
implication that O.crinita Cherbonnier & Guille should also be
referred to the synonymy on the basis that it exhibits the extreme
spiny form of O. hirsuta.

42. Ophiodyscrita instratus (Murakami, 1944) n. comb.
SEE. Murakami, 1944: 272 (as Ophiostegastus instratus);
A.M.Clark, 1968: 320 (as Ophiostegastus instratus; discussion)
810124A/4 (1).
Ala Gala, Galle, Sri Lanka.

Subtidal rock, 10-15 m.

MATERIAL.
COLLECTION SITES.
HABITAT AND DEPTH.

REMARKS. This specimen, apart from its smaller size and fewer
naked disc plates, accords so well with Murakami’s (1944) descrip-
tion of Ophiostegastus instratus that its identity is in no doubt. The
species is, however, transferred to the genus Ophiodyscrita H.L.
Clark, 1938 (type-species O. acosmeta H.L. Clark), with
Ophiostegatus Murakami, 1944 (of which instratus is the type-
species) reduced to a junior synonym of Ophiodyscrita. The
distinctness of two genera has been questioned by A.M. Clark
(1968) and Guille & Vadon (1985) on the grounds of variation of
granulation with increased specimen size. Tabulation of measure-
ments (Table 1) taken from original species descriptions and similar
details of the specimens from Sri Lanka, shows an interesting
picture. From this table it becomes apparent that only two species
can be recognised: a) Ophiodyscrita instratus (Murakami, 1943)(d.d.
= 7mm) of which the larger Ophiostegastus novaecaledoniae Guille
& Vadon (d.d. = 9-11 mm) is a synonym, being an extreme form of
instratus in which many disc plates, including the radial shields,
have become prominent (convex) and naked of granules; this species
possesses supplementary oral shields (granule covered in small
specimens < 7 mm d.d.) and b) O. acosmeta H.L. Clark (d.d. = 5
mm) with which O. pacifica (Murakami, 1943)(d.d. 4 mm) and
Ophiostegastus compsus A.M. Clark (1968) type locality Bahrain
(d.d. = 8-10.5 mm) appear to be conspecific. O. acosmeta has an
even covering of granules over the disc which are gradually lost only
from the oral shields (as in the type of acosmeta; d.d. = 5 mm) and
adoral plates (as in the type series of compsus; d.d. = 8-10.5 mm;
though A.M. Clark (1968) does note that the largest paratype of
compsus (d.d. = 10.5 mm) has a small bare patch dorsally at the base
of 4 of the arms). Supplementary oral shields are absent from
compsus, according to A.M. Clark, and are not recorded for either
acosmeta or pacifica. In both instratus and acosmeta, as recognised
herein, it is clear that arm spine number increases with size.

There is clearly insufficient justification for recognising
Ophiodyscrita and Ophiostegastus as separate genera on the basis of
the extent of disc granulation, for it is clear (see Clark & Rowe,
1971) that such differences occur between species included within

| COLLECTION SITES.

| HABITAT AND DEPTH.

INDIAN OCEAN ECHINODERMS

79

Complete cover dorsal and ventral
Complete cover dorsal and ventral except 2 oral shields (Clark & Rowe

Complete cover dorsal and ventral except radial plate at base of deach arm,
each mid marginal plate and ventrally, each of the oral shields

Complete except 3 plates at base of each arm; each mid marginal; each oral
shield and supplementary oral shield

Complete except each oral shield and adoral shield (A.M. Clark notes a
small bare patch as base of 4 arms of one paratype d.d. = 10.5 mm)

Table 1. Details of species Ophiodyscrita acosmeta H.L. Clark* and O. instratus (Murakami)*
Taxon d.d.(mm) a.sp. l.a.sp. S.0.S. Granulation (disc)
Ophiocryptus* 4.00 6-5 1/3 seg. -?

pacificus Murakami, 1943
Ophiodyscrita* 5.0 8(7) 1/2 seg. -?

acosmeta H.L. Clark, 1938 (1971: 135)
Sindbad spec.* 5.3 6-5 <l/2seg. +(granule

covered

Ophiostegastus* 7.00 7 1/3 seg. + (naked)

instratus Murakami, 1944
Ophiostegastus* 8-10.5 9 <I/2seg. —-

compsus A.M. Clark, 1968
Ophiostegastus* 9-11 9-10 <1/2 seg. + (naked)

novaecaledoniae
Guille & Vadon, 1985

Many dorsal plates, including radial shields, marginal plates and ventral
plates including oral, supplementary oral and adoral shields bare of
granules

d.d. = disc diameter; a.sp. = number of arm spines; |.a.sp. = length of arm spines; s.o.s. (+/—) = presence/absence of supplementary oral shields.

the recognised limits of other ophiodermatid genera (e.g. Ophiopeza
& Ophiarachnella). Similarly, the occurrence of supplementary oral
shields is also a variable character. The recognition of Ophiodyscrita
within the family appears, therefore, to rely, more or less solely, on
the extension of granulation along the arms. The genus is closely
related to Ophiopeza with which it shares the possession of a triangle
of 3 plates between the radial shields (see Vail & Rowe, 1989). The
record of O. instratus from Sri Lanka greatly extends the known
distribution of the species from Japan and New Caledonia (S.W.
Pacific). The distribution of the genus, Ophiodyscrita (syn:
Ophiostegastus ) is clearly widespread in the Indo-West Pacific

region.

43. Ophiopsammus yoldii (Liitken, 1856)

SEE. A.M. Clark, 1968: 317; Clark & Rowe, 1971: 90; 127; Vail &
Rowe, 1989: 277; Rowe & Gates, 1995: 402.

MATERIAL. 810430A/22b (1).

Ug Seukundo, Pula Wé, Sumatra.
Coral rubble; 9 m.

REMARKS. Nearly half of the disc of this small specimen has been
lost leaving the remaining disc (d.d. = c. 6 mm) and three of the
original arms, which are also damaged (a.1. = c. 17 mm; d.d./a.l. =.
3+: 1). Arising from the damaged edge of the disc are three new,
minute arms at slightly different stages of growth judging by the
relative development of the ventral arm plates on each arm. These
arms are also damaged but the longest is judged to have been not
more than c. 3-4 mm in length. Following Vail & Rowe’s (1989)
revision of the genus Ophiopsammus, there is no reason for not
identifying the specimen from Pula Wé as O. yoldii, for it appears to
match their criteria for the species even though it is of small size. The
species is not known to be fissiparous. Although this may be the first
observation of fissiparity in O. yoldii, the development of six arms,
in this case, may be an unusual response to severe damage, rather
than being related to an asexual reproductive strategy. This matter
requires further investigation.

| Family OPHIURIDAE

44. Ophiolepis cincta Miiller & Troschel, 1842

SEE. Clark & Rowe, 1971: 90; 129; Clark & Courtman Stock,

1976: 189: Sloan et al, 1979: 115-117; Rowe & Gates, 1995: 399.
MATERIAL. 801212B/1 (1).
COLLECTION SITES. Chetlat, Lakshadweep (Laccadive) Islands.

HABITAT AND DEPTH. Coral rubble; 8 m.

Class Echinoidea

Family CIDARIDAE

1. Eucidaris metularia (Lamarck, 1816)

SEE. Clark & Rowe, 1971: 140; 150; Clark & Courtman Stock,
1976: 215; Sloan ert al., 1979: 117 Rowe & Gates, 1995: 195.
810426A/4 (1), 810501E/12 (1).

Rubiah, Ug Seukundo, Pula Wé, Sumatra.

MATERIAL.
COLLECTION SITES.

HABITAT AND DEPTH. Coral reef, coral aggregate; 10 & 14 m.

Family DIADEMATIDAE

2. Diadema setosum (Leske, 1778)

SEE. Clark & Rowe, 1971: 140; 153; Clark & Courtman Stock,
1976: 226; Sloan et al., 1979: 118; Price, 1983: 73; Rowe & Gates,
1995: 207.

MATERIAL. 801027A/1 (1), 801030A/la,b (4), 810212A/1 (1),
810420A/1 (1), 810420A/4 (1), 810426A/3 (1), 810426B/5 (2),
810426B/12 (1), 810427D/5 (1 juvenile), 810428D/4 (2), 810501G/
4 (1 juvenile), 8105011/1 (1), 810502D/1 (1, broken).

COLLECTION SITES. Muscat, Oman; Unawatuna, nr Galle, Sri
Lanka; Rubiah, Klah, Ug Murung, Ug Tapa Gadja, Ug Seukundo,
Pula Wé, Sumatra.

HABITAT AND DEPTH. Subtidal rock, subtidal rock / sand, subtidal
rock / coral, coral reef; 0-20 m.

REMARKS. A number of these specimens are juveniles, as small as
10 mm h.d., and with banded spines. The characteristic elongate,
tridentate pedicellariae of D. setosum (see Clark & Rowe, 1971) are

80

absent from all specimens examined. The remaining character of the
red (or in some cases a faded, cream) ring on the anus is the only
means of distinguishing this species from D. savignyi. In the field
the two species are easily distinguished by the colour pattern, D.
savignyi lacking the red ring and having characteristic, irridescent
blue lines along the upper interamulacra.

3. Echinothrix calamaris (Pallas, 1774)
SEE. Clark & Rowe, 1971: 140; 153; Clark & Courtman Stock,

1976: 226; Rowe & Gates, 1995: 208.

MATERIAL. 801111A/2 (1), 810422B/1 (1), 810425C/4 (1),
810426B/4 (1), 810426B/13 (1), 810501K/2 (1), 810501K/3 (1).

COLLECTION SITES. Muscat, Oman; S. Sabang Bay (to S. of Klah),
E. Sabang Bay, Rubiah, Ug Seukundo, Pula Wé, Sumatra.

HABITAT AND DEPTH. Subtidal rock, subtidal rock / coral / sand,

coral reef; 0-20 m.
Family STOMECHINIDAE

4. Stomopneustes variolaris (Lamarck, 1816)
SEE. Clark & Rowe, 1971: 140; 153; Clark & Courtman Stock,
1976: 228; Sloan et al., 1976: 118; Rowe & Gates, 1995: 246.
810123B/4 (1).
Galle, Sri Lanka.

Subtidal rock; 5 m.

MATERIAL.
COLLECTION SITES.

HABITAT AND DEPTH.

Family TEMNOPLEURIDAE

5. Mespilia globulus (Linnaeus, 1758)

SEE. Clark & Rowe, 1971: 140; 155; Rowe & Gates, 1995: 250.
810502F/5 (1).
Klah, Pula Wé, Sumatra.

Subtidal rock; 5 m.

MATERIAL.
COLLECTION SITES.

HABITAT AND DEPTH.
6. Microcyphus ceylanicus Mortensen, 1942

SEE. Clark & Rowe, 1971: 140; 156.
820204A/11 (1).
SW Kalpitiya, Sri Lanka.

MATERIAL.
COLLECTION SITES.

HABITAT AND DEPTH. Coral reef; 3—5 m.

7. Salamacis bicolor L. Agassiz, 1846

SEE. Clark & Rowe, 1971: 140; 156; Clark & Courtman Stock,
1976: 232.
MATERIAL. 810126B/1 (1).

Galle, Sri Lanka.

Coral reef; 4—5 m.

COLLECTION SITES.

HABITAT AND DEPTH.

Family TOXOPNEUSTIDAE

8. Toxopneustes piloleus (Lamarck, 1816)

SEE. Clark & Rowe, 1971: 142; 156; Clark & Courtman Stock,

1976: 234; Rowe & Gates, 1995: 258.

801114C/1 (1); 810424A/1 (1).

Muscat, Oman; W. Klah, Pula Wé, Sumatra.
Coral reef; 10-12 m.

MATERIAL.
COLLECTION SITES.

HABITAT AND DEPTH.

Family PARASALENIIDAE

9. Parasalenia gratiosa A. Agassiz, 1863

SEE. Clark & Rowe, 1971: 142; 157; Rowe & Gates, 1995: 233.
810422B/5 (2).
S. Sabang Bay (to S. of Klah), Sumatra.

MATERIAL.
COLLECTION SITES.

HABITAT AND DEPTH. Coral conglomerate; 2—8 m.

Family ECHINOMETRIDAE

10. Echinometra mathaei (de Blainville, 1825)

SEE. Clark & Rowe, 1971: 142; 157; Clark & Courtman Stock,
1976: 239; Sloan et al., 1979: 119; Price, 1983: 76; Rowe & Gates,
1995: 211.

MATERIAL. 801111A/1 (5), 810204A/10 (1).

COLLECTION SITES. Muscat, Oman; SW Kalpitiya, Sri Lanka.

HABITAT AND DEPTH. Coral reef, rock / coral / sand; 0-5 m.

REMARKS. Two forms of this species are represented. The speci-
men from Sri Lanka is relatively large, with h.d. = 48.7 mm. It has 4
pore-pairs per arc, the spines are uniformly pale blue/green and the
test, when cleaned, is whitish in colour. The 5 specimens from
Muscat, Oman are smaller, ranging in size from h.d. = 10-21 mm.
They have 5 pore-pairs per arc, the spines are dark olive green tipped
with lilac/brown and the test, when cleaned, is greenish in colour.
Echinometra mathaei is clearly a complex species which is in need
of critical investigation to determine whether, as it is currently
identified, it comprises a single species or more than one closely
related species (see Mortensen, 1943; Tsuchiya & Nishira, 1984).

11. Echinostrephus molaris (de Blainville, 1825)
SEE. Clark & Rowe, 1971: 142; 157; Clark & Courtman Stock,
1976: 239-240: Sloan et al., 1979: 119; Rowe & Gates, 1995: 212.

MATERIAL.
810427D/5 (1), 810502G/4 (1)

COLLECTION SITES. Chetlat, Lakshaweep (Laccadive) Islands; Ug
Bau, Lho Pria Laot, Ug Murung, Klah, Pula Wé, Sumatra.

HABITAT AND DEPTH.
coral; 0-40 m.

801210B/6 (1), 810423A/5 (1), 810427B/3 (1), |

A.R.G. PRICE AND F.W.E. ROWE

Coral reef, subtidal rock, subtidal rock / | —

INDIAN OCEAN ECHINODERMS
DISCUSSION

Echinoderm collections from the Sindbad Voyage have yielded at
least 44 species of ophiuroids and 11 species of echinoids. Species
totals for each area sampled, with the corresponding zoogeographic
subdivision used by Clark & Rowe (1971), are given in Table 2.
Despite the small size of Pula Wé (c. 20 km x 12 km), 32 ophiuroids
and 7 echinoids (71% of all species recorded) were encountered at,
although not necessarily restricted to, this island. This high species
richness is partly a reflection of the sampling intensity in Pula Wé,
but is equally or more an indication of high biodiversity known for
coral reefs in the SE Asia region (Sheppard, 1987; Wells & Price,
1992).

Of the ophiuroids collected, O (A.) purpurea and O. trilineata
were the most common, occurring in more than 20% of the ophiuroid

Table 2. Ophiuroid and echinoid species numbers for each area of the
Indian Ocean sampled during the Sindbad Voyage. (total ophiuroid
species recorded for all regions = 44 ; total echinoid species recorded
for all regions = 11)

Sampling area and equivalent No. of species recorded

zoogeographic subdivision OPHIUROIDS ECHINOIDS
Oman (SE Arabia) 2 4
S India (W. India & Pakistan) 1 0
Laccadive (Maldive area) Fi |
Sri Lanka (Sri Lanka area) 7 |
Sumatra (Indonesia / East Indies) ai I

Of the 44 ophiuroid species collected, ten result in new area
records (Table 3), as follows: W India (Amphioplus (Lymanella)
sp.); Sri Lanka (Ophiactis modesta, Ophiarachna robillardi,
Ophiodyscrita instratus); Maldives area (Cryptopelta granulifera,
Ophiochaeta hirsuta); and Indonesia / East Indies (Amphiura
(Amphiura) dejectoides, Amphiura (Amphiura) micra, Amphioplus
(A.) stenaspis, Ophiogymna pellicula).

Table 3. New area records and previously known distribution of
ophiuroid species recorded in the Indian Ocean during the Sindbad
Voyage

Species New arearecord Previously known distribution

Amphiura Indonesia/East Red Sea; E. Africa (Madagascar)
(Amphiura) Indies
dejectoides

Amphiura Indonesia/East N. Australia and possibly E. Africa/
(Amphiura) micra Indies Madagascar

Amphioplus (A.) Indonesia/East N. Australia and possibly E. Africa/
Stenaspis Indies Madagascar

Amphioplus West India A. (L.) andreae from Indonesia/
(Lymanella) sp. (Beypore) East Indies, and A. (L.) laevis from

Indo-West Pacific

W. India & Pakistan, and eastwards
from Bay of Bengal to Hawaiian
Is. but not Philippines, and
possibly also E.Africa/Madagascar

Ophiactis modesta Sri Lanka

Ophiogymna Indonesia/East Bay of Bengal and N. Australia
pellicula Indies

Cryptopelta Maldives Mascarene Is. (Mauritius, Réunion,
granulifera Rodrigues group) and N. Australia

Ophiarachna Sri Lanka Mascarene Is.
robillardi

Ophiochaeta Maldives Is. of W. Indian Ocean, Indonesia/
hirsuta East Indies, N. Australia and S.

Pacific Is.
Ophiodyscrita Sri Lanka Japan and New Caledonia

:
:

instratus (SW Pacific)

81

samples. These species also occupied a wide range of substrata and
depths (2—30m). Other species occurred in less than 10% of the
ophiuroid samples, and generally occupied fewer habitats and a
narrower depth range. The echinoid fauna was less diverse, although
some species were very common, in particular D. setosum, E.
calamaris and E. molaris (a coral rock borer), which occurred in
36%, 19% and 14 % of the echinoid samples respectively. These
echinoids were found in a wide range of habitats and depths, up to 40
m in the case of E. molaris. A more comprehensive ecological
analysis of echinoderms of Pula Wé, Sumatra is to be undertaken
following completion of the taxonomic appraisal of the crinoids.

ACKNOWLEDGEMENTS. We wish to thank the staff at the Natural History
Museum, London, for access to the collections and other facilities. We are
grateful of Dr R. Dalley, P. Hunnam, P. Dobbs and D. Tattle for their
considerable assistance during field work. One of us (A.R.G.P.) would also
like to thank T. Severin, leader of the Sindbad Voyage, for the kind invitation
to participate in the expedition which was made possible by generous support
from the Ministry of Natural Heritage and Culture, Sultanate of Oman.
Thanks are due to L. Marsh for identifying several ophiuroids. Financial
assistance to A.R.G.P. from the Leverhulme Trust is gratefully acknowl-
edged.

REFERENCES

Aziz, A. 1981. Fauna echinodermata dari Terumbu Karang Pulau Pari, Pulau-Pulau
Seribu. Oseanologi di Indonesia 14: 41—SO.

Baker, A.N. 1980. Euryalinid Ophiuroidea (Echinodermata) from Australia, New
Zealand and the south-west Pacific. New Zealand Journal of Zoology 7 : 11-83.
Bussarawit, S. & Rowe, F.W.E. 1985. A new species in the ophiocomid genus
Ophiocoma (Echinodermata: Ophiuroidea) from the west coast of Thailand, Andaman

Sea. Phuket Marine Biological Center Research Bulletin 35: \-6.

Bussarawit, S. in prep. Taxonomic study of echinoderms (other than Holothuroidea)
from Phuket Island and along the west coast of Thailand. Phuket Marine Biological
Center Research Bulletin.

Cherbonnier, G. & Guille, A. 1978. Faune de Madagascar. 48. Ophiurides. Centre De
La Recherche Scientifique, Paris: CNRS.

Clark, A.M. 1953. A revision of the genus Ophionereis. Proceedings of the Zoological
Society of London 123(1): 65-94.

1967. Notes on the family Ophiotrichidae (Ophiuroidea). Annals and Magazine

of Natural History 9: 637-655.

1968. Notes on some tropical Indo-Pacific ophiotrichids and ophiodermatids
(Ophiuroidea). Bulletin of the British Museum (Natural History ), Zoology 16(7):
275-322.

Clark, A.M. & Courtman-Stock, J. 1976. Echinoderms of Southern Africa. 277 p.
London: British Museum (Natural History), London.

Clark, A.M. & Rowe, F.W.E. 1971. Monograph of Shallow-Water Indo-West Pacific
Echinoderms. 238 p. British Museum (Natural History), London.

Clark, H.L. 1938. Echinoderms from Australia. Memoirs of the Museum of Compara-
tive Zoology, Harvard 55 : 1-596.

Devaney, D.M. 1970. Studies on ophiocomid brittlestars. 1. A new genus (Clarkcoma)
of Ophiocominae with evaluation of the genus Ophiocoma. Smithsonian Contribu-
tions to Zoology No. 51: 1-41.

1974. Shallow-water asterozoans of southeastern Polynesia 2. Ophiuroidea.
Micronesica 10: 105-204.

Guille, A. & Vadon, C. 1985. Les ophiures littorales de Nouvelle-Calédonie. Bulletin
du Muséum National d'Histoire Naturelle, Paris (4)7, Sect. A., no. 1: 61-72.

Hoggett, A.K. 1991. The genus Macrophiothrix (Ophiuroidea: Ophiotrichidae) in
Australian waters. Invertebrate Taxonomy 4: 1077-1046.

— 1992. Taxonomic and systematic position of the brittlestar genus Macrophiothrix
H.L. Clark (Echinodermata: Ophiuroidea). PhD Thesis, University of Queensland.
xviii + 412pp.

James, D.B. 1989. Echinoderms of Lakshadweep and their zoogeography. Bulletin of
the Centre for Marine Fisheries Research Institute 43: 97-144.

Lincoln, R.J. & Shields, J.G. 1979. Invertebrate Animals: Collection and Preserva-
tion. 150 p. British Museum (Natural History) & Cambridge University Press.

Marsh L.M. & Price, A.R.G. 1991. Indian Ocean echinoderms collected during the
Sindbad Voyage (1980-81): 2. Asteroidea. Bulletin of the British Museum (Natural
History ), Zoology 57(1): 61-70.

82

Mortensen, T. 1943.A Monogaph of the Echinoidea. III. Echinidae, Strongylocentridae,
Paraseleniidae, Echinometridae. Reitzel, Copenhagen, pp. 1446.

Murakami, S. 1943. Reports on the ophiurans of Palao, Caroline Islands. Journal of
the Department of Agriculture, Kyiisyii Imperial University 7(4): 159-204.

Murakami, S. 1944. Note on the ophiurans of Amakusa, Kyiisyii. Journal of the
Department of Agriculture, Kyiisyii Imperial University 7(8): 259-280.

Nagabhushanam, A.K. & Rao, G.C. 1972. An ecological survey of the marine fauna
of Minicoy Atoll (Laccadive Archipelago Arabian Sea). Mitteilungen Zoologisches
Museums Berlin 48(2): 265-324.

Price, A.R.G. 1983. Echinoderms of Saudi Arabia. Echinoderms of the Arabian Gulf
coast of Saudi Arabia. Fauna of Saudi Arabia 5 : 28-108.

Price A.R.G. & Reid, C.E. 1985. Indian Ocean echinoderms collected during the
Sindbad Voyage (1980-81): 1. Holothurioidea. Bulletin of the British Museum
(Natural History ), Zoology 48(1): 1-9.

A.R.G. PRICE AND F.W.E. ROWE

Rowe, F.W.E. & Gates, J. 1995. Echinodermata. In Wells, A. (ed.) Zoological Cata-
logue of Australia Vol. 3. CSIRO, Melbourne, Australia xiii, pp. 1— 510.

Sheppard, C.R.C. 1987. Coral species of the Indian Ocean and adjacent seas: a
synonymized compilation and some regional distributional patterns. Atoll Research
Bulletin 307: 1-32.

Sloan N.A., Clark A.M. & Taylor, J.D. 1979. The echinoderms of Aldabra and their
habitats. Bulletin of the British Museum (Natural History ), Zoology 37(2): 81-128.

Tsuchiya, M. & Nishihara, M. 1984. Ecological distribution of two types of the sea-
urchin Echinometra mathaei (Blainville), on Okinawa reef flat. Galaxea 3: 131-143.

Vail, L.L. & Rowe, F.W.E. 1989. Status of the genera Ophiopeza and Ophiopsammus
(Echinodermata: Ophiuroidea) in Australian waters, with the description of a new
species. Proceedings of the Linnean Society of New South Wales 110(3): 267-288.

Wells, S.M. & Price, A.R.G. 1992. Coral Reefs — Valuable but Vulnerable. 40 p. WWF
— World Wide Fund for Nature, Gland, Switzerland.

EE

Bull. nat. Hist. Mus. Lond. (Zool.) 62(2): 83-99

Issued 28 November 1996

Rare cyclopoid copepods (Crustacea) from
Mediterranean littoral caves

D. JAUME AND G.A. BOXSHALL

Department of Zoology, The Natural History Museum, Cromwell Road, London SW7 5BD, UK

SYNOPSIS.

Three cyclopoid copepods are reported from anchihaline cave habitats on Mallorca. Both sexes of Cyclopina esilis

Brian are redescribed. Sexual dimorphism in the mandibular exopod, as discovered in C. esilis, has not previously been reported
for any cyclopinid. The male of the primitive marine cyclopid Neocyclops (Protoneocyclops) mediterraneus (Kiefer) is described
in detail for the first time and the characters distinguishing this species are discussed. Both sexes of Euryte longicauda Philippi
are redescribed. The genus Euryte Philippi is briefly reviewed and the characters used to differentiate species are critically
reevaluated. It is concluded that all three genera, the cyclopinid genus Cyclopina Claus and the primitive cyclopids Neocyclops
Gurney and Euryte, are in urgent need of revision, but that this process will be hampered by the inadequacy of published

descriptions and the lack of available type material.

INTRODUCTION

Anchihaline cave habitats are rich sources of interesting and unusual
crustaceans. Copepods of immense phylogenetic significance have
been discovered in such caves in the last decade, including the
platycopioid Antrisocopia Fosshagen, the misaphrioid
Speleophriopsis Jaume & Boxshall, and the calanoid Erebonectes
Fosshagen (Fosshagen & Iliffe, 1985; Jaume & Boxshall, 1996).
There have been few reports of cyclopoid copepods in anchihaline
caves. Recently, however, Rocha & Iliffe (1991, 1994) described a
new family of cyclopoids, the Speleoithonidae, and the primitive
cyclopid Troglocyclops, from caves on the Bahamas Islands. During
our studies of the copepod fauna of Mallorcan caves we discovered
numerous cyclopoids, including the three rare species described in
this account. All three species were originally described from the
Mediterranean Basin. All have been the subject of considerable
taxonomic confusion because their original descriptions were inad-
equate and we have attempted to clear up some of this confusion at
the same time as presenting full redescriptions.

THE CAVES

The copepods were collected from four caves located on the East
coast of Mallorca, less than 20 m inland. These caves occur in two
different types of substratum. Cova ‘C’ de Cala Varques and Es
Secret des Moix are in Tortonian (10 Myr BP), coral reef-derived,
porous calcarenites and mixing-zone corrosion processes seem to
have played an important role in their development. Cova de na
Barxa and Cova de na Mitjana are in Triassic, fissured limestones.
All these caves have subaerial entrances; the difficulty of access can
be deduced from their topographies, published elsewhere (see be-
low). The water conditions varied from cave to cave: In Es Secret des
Moix, the sampled lake (that located closest to the entrance) was
completely marine (i.e., in water salinity, a detectable swell, the
nature of the accompanying fauna), as was the lake in Cova de na
Mitjana. Cova ‘C’ de Cala Varques and Cova de na Barxa are typical
anchihaline caves (in the sense of Stock et al., 1986), with a thin
layer of fresh water on the top of the deeper saline waters of the
lakes.

© The Natural History Museum, 1996

Sampling was undertaken using meat-baited traps placed at dif-
ferent depths in the cave lakes and left for several days, and by using
a hand-held plankton net with an extensible handle. The terminology
used in the descriptions follows Huys & Boxshall (1991).

SYSTEMATICS

Order CYCLOPOIDA Burmeister, 1834
Family CYCLOPINIDAE Sars, 1913
Subfamily CYCLOPININAE Kiefer, 1927
Genus Cyclopina Claus, 1863

Cyclopina esilis Brian, 1938
(Figs 1-4)
Cyclopina cf. kieferi: Herbst (1953; 1962)

MATERIAL EXAMINED. Cova de na Mitjana (Capdepera). UTM
coordinates: 539.10; 4390.95. Topography published by Ginés er al.
(1975): 96 individuals, both sexes (BMNH 1995. 1331-1340).
Collected by D. Jaume, 17 July 1994.

ADULT FEMALE. Body (Figs 1A, B) cyclopiform, up to 0.37 mm
long. Prosome 5-segmented, about 1.7 times longer than urosome.
Rostrum developed, oval. Posterolateral margins of cephalosome
vaulted. First pedigerous somite free, partially concealed by dorsal
and posterolateral extensions of cephalosome. Second to fourth
pedigerous somites with evenly rounded posterolateral angles.
Urosome 5-segmented, with genital and first abdominal somites
completely fused to form genital double-somite. Serrate hyaline frill
adorning posterodorsal margin of fifth pedigerous somite, posterior
margins of genital double-somite and abdominal somites 2 and 3,
and posterolateral margins of anal somite; degree of serration vary-
ing directly with body size. Genital double-somite (Fig. 1D)
symmetrical, 1.6 times longer than wide, expanded anteriorly. Sin-
gle copulatory pore opening mid-ventrally at about two-fifths of
distance along double-somite. Paired gonopores located laterally,
each covered by operculum armed with short spinous process, 1

84 D. JAUME AND G.A. BOXSHALL

Fig. 1. Cyclopina esilis Brian, 1938, adult female. A, body, dorsal view; B, lateral; C, antennule; D, genital double-somite, lateral; E, fifth leg; F-G, dorsal
view of anal somite and caudal rami, showing variation with body size in the position of the lateral seta of the caudal ramus.

seta, and | long flanged spine (Fig. 1D). Anal somite (Figs 1F, G) variable, ranging from two-fifths (Fig. 1G) to three-fifths of distance
bearing smooth operculum. Caudal rami longer than anal somite, along distal margin (Fig. 1F).

about 2.6 to 3.3 times longer than wide; proportional length related Antennules (Fig. 1C) symmetrical, 10-segmented, shorter than
to body size. Armature consisting of 6 setae; position of seta II prosome (Fig. 1B). Segmental fusion pattern and armature as fol-

|
|
:

|

CYCLOPOIDS FROM LITTORAL CAVES

mandibular exopod.

lows: segment | (corresponding to fused ancestral segments I and
II), 3 setae; segment 2 (corresponding to fused ancestral segments III
to V), 5 setae; segment 3 (fused segments VI to IX), 8 setae; segment
4 (fused segments X and XI), 4 setae; segment 5 (fused segments XII

| to XIV), 6 setae; segment 6 (fused segments XV to XX, partial

suture present between segments XVI and XVII), 6 setae + aesthetasc;
segment 7 (fused segments XXI to XXIII), 3 + aesthetasc; segment
8 (XXIV), 2 setae; segment 9 (XXV), 1 + aesthetasc; segment 10
(fused segments XXVI to XXVIII), 7 + aesthetasc.

Antenna (Fig. 2A) 4-segmented. Fused coxa and basis short,
about 1.5 times longer than wide, armed with | inner basal seta
distally and 1 long seta (representing exopod) on outer margin.

85

| Fig.2. Cyclopina esilis Brian, 1938, A and C—F, adult female, B, adult male. A, antenna; B, mandible; C, maxillule; D, maxilla; E, maxilliped; F,

Endopod 3-segmented. Proximal segment with | seta at about two-
thirds of distance along inner margin; segment covered by long
spinules on anterior surface. Second segment with 2 lateral and 3
distal setae (one of them claw-like) along inner margin. Distal
segment with 7 distal setae, one of them claw-like. Secondary
ornamentation on segments as figured.

Mandible (Figs 2B, F) with gnathobase armed with 10 unequal,
sharp teeth plus 1 dorsal seta; row of 13 spinules located subdistally.
Palp well developed; basis elongate, with patch of setules and 1
subdistal seta along inner margin. Exopod (Fig. 2F) inserted at about
midway of distance along outer margin of basis; 4-segmented; setal
formula 1,1,1,2; distal, brush-like seta somewhat shorter and thicker

86

D. JAUME AND G.A. BOXSHALL

BZ
- . os y = MG
ft Ps . ~
ed Hyaat f SAT. Sa\ AN
4 ny \ ae
Fy) | oe in Me NY
ad . ‘Ge % " me
re w/ * =A si
2 ‘ - 4 Yo e ~
S

‘ {qs 8

‘nnn f ewe conus
NS Ninn

Fig. 3. Cyclopina esilis Brian, 1938, adult female swimming legs, posterior view. A, leg 1; B, leg 2; C, leg 3; D, leg 4.

than others, with brush of 6 setules on tip. Endopod 2-segmented,
shorter than exopod, setal formula 3,6.

Maxillule (Fig. 2C) with well developed praecoxal arthrite, armed
with 9 thick, unequal spines around distal margin plus isolated seta
on posterior surface. Coxa and basis fused: coxal epipodite repre-
sented by 2 unequal setae; coxal endite represented by small
cyclindrical knob armed with | seta. Proximal and distal endites of
basis discrete, bearing 3 and 2 setae respectively. Endopod 1-
segmented, bearing 7 setae. Exopod 1-segmented, armed with 4
distal setae and marginal row of long setules.

Maxilla (Fig. 2D) well developed, 4-segmented. Praecoxa and
coxa partially fused, endites with setal formula 3,1,3,3. Basis with
large endite bearing claw-like spine plus 2 unequal setae. Endopod
2-segmented; proximal segment representing fused first and second
ancestral endopodal segments; distal representing fused third and
fourth ancestral segments; endopod setation formula (2+2),(2+4).

Maxilliped (Fig. 2E) slender, 6-segmented. Praecoxa and coxa
fused forming syncoxa, bearing 3 (coxal) endites with setal formula
1,3,2. Basis with medial margin swollen, ornamented with marginal
row of long setules; 2 setae implanted subdistally on medial margin.

CYCLOPOIDS FROM LITTORAL CAVES

87

Fig. 4. Cyclopina esilis Brian, 1938, adult male. A, body, dorsal; B, lateral; C, genital somite, ventral; D, antennule; E, fifth leg.

Endopod 4-segmented, setal formula 0,0,1,4; transverse row of
setules on segment 3.

Swimming legs | to 4 (Fig. 3) biramous, both rami 3-seg-
mented. Legs subequal in size except first, somewhat reduced.
All legs richly ornamented with denticles, as figured; anterior
surface of coxae covered by small denticles, omitted from fig-
ures. Spines on exopodal segments flanged with serrate hyaline
frill; distal spine on third exopodal segment of legs 1 and 2, and
spines on endopod of leg 4 flanged only on one side. Armature as
follows:

Coxa Basis Exopod Endopod
Leg | 0-1 1-I -1;F-1;01,1,4 0-1;0-1;1,2,3
Leg 2 0-1 1-0 I-1;1-1;I11,1,5 0-1;0-2;1,2,3
Leg 3 0-1 1-0 I-1;J-1;111,1,5 0-1;0—2;1,2,3
Leg 4 0-1 1-0 -1;1-1;IL1,5 O-1;0-II;1,2,1+1

Fifth legs (Fig. 1E) uniramous, 2-segmented, joined by naked
intercoxal sclerite. Coxa and basis fused forming trapezoidal
protopodal segment; inner margin with row of long setules; outer
margin with long, smooth seta subdistally. Distal segment (exopod)
about 1.6 times as long as wide, produced distally into median

88

process bearing 1 long, plumose seta; 1 flanged spine present
subdistally on each side of process, outer stouter, longer than
segment; inner spine less than half length of outer spine; spinule
ornamentation on segment as figured.

ADULT MALE. Body (Figs 4A, B) up to 0.38 mm long, more
slender than female. Urosome 6-segmented, with genital somite
(Fig. 4C) symmetrical, slightly expanded laterally; paired gonopores
opening ventrally at posterior border of somite; genital opercular
flaps each armed with tiny inner spine plus 2 long, outer setae.

Antennules (Fig. 4D) 15-segmented, symmetrical, digeniculate.
Geniculations between segments homologous with ancestral seg-
ments XV and XVI (9 and 10), and between XX and XXI (13 and
14). Segment 9 (XV) cup-shaped, forming sheath around proximal
half of segment 10 (XVI). Segmental fusion pattern and armature as
follows: segment | (corresponding to fused ancestral segments I and
II), 3 setae + aesthetasc; segment 2 (fused ancestral segments III to
V), 5 setae; segment 3 (fused ancestral segments VI and VII), 4 setae;
segment 4 (VIII), 2 setae; segment 5 (partially fused ancestral
segments IX to XI), 6 setae; segments 6 to 9 (XII to XV), 2 setae
each; segment 10 (XVI), | pectinate spine, 1 seta + aesthetasc;
segments 11 and 12 (XVII and XVIII), 1 pectinate spine and 1 seta
each; segment 13 (fused ancestral segments XIX and XX), 1 pecti-
nate spine, | modified flattened spine, and 1 seta; segment 14 (fused
ancestral segments XXI and XXII), 1 modified flattened, spine
plate, 1 seta + aesthetasc; segment 15 (fused ancestral segments
XXIII to XXVIID, 11 + aesthetasc.

Segmentation and setation of other cephalosomic appendages and
swimming legs | to 4 as in female, except mandibular palp (Fig. 2B);
distal brush-like seta on exopod much shorter and thicker, setules on
tip longer than in female.

Fifth legs (Fig. 4E) resembling female condition, but with 2
additional setae implanted subdistally along inner margin of exopod.

REMARKS. The Cyclopina from the cave on Mallorca belongs to
the group of species in the genus that displays a female leg 5 with the
inner spine of distal segment less than half the length of the outer
spine, the latter being longer than the segment itself. This group
comprises Cyclopina esilis Brian, 1938, C. americana Herbst, 1982,
and C. cuipora Lotufo, 1994. The taxon from Mallorca differs
clearly from C. cuipora. The female antennule is 10-segmented (not
12-segmented as in C. cuipora), and the intercoxal sclerite of leg 4
is almost completely smooth (not powerfully ornamented with
several rows of thick spinules as in C. cuipora) (Lotufo, 1994).
Differences from C. americana include the short, subquadrate cau-
dal rami (Herbst, 1982) which contrast with the elongate (2.5 to 3.2
times as long as wide) caudal rami of the Mallorcan taxon.

The Cyclopina from Mallorca is identified as C. esilis, based on
the segmentation of the female antennule, the setation of leg 5 and
the proportions of the caudal rami. We noted variation in the
proportional length of the caudal rami within the Mallorcan popula-
tion. A similar degree of variability in length of the caudal rami has
been reported in C. esilis (Brian, 1938; Monchenko, 1979).

Apparent differences in the armature of mouthparts have not been
evaluated since we suspect that the armature of mouthparts in C.
esilis (as in most species of Cyclopina) were inadequately described
in the original descriptions. This is evident in the presence of a coxal
endite, armed with 1 seta, on the maxillule of the Cyclopina from
Mallorca. This character state (presence of coxal endite) had never
previously been noted in Cyclopina and was known only from
Cyclopinodes elegans (T. Scott, 1894) in the family Cyclopinidae
(Huys & Boxshall, 1991). The coxal endite may well be present on
the maxillule of all Cyclopina species. It is present in C. gracilis
Claus, 1863 from the coast of Scotland (BMNH 1986.377) (pers.

D. JAUME AND G.A. BOXSHALL

obs.), and perhaps also in C. oblivia Monchenko, 1981, according to
Monchenko (1989: Fig. 9).

The Cyclopina reported by Herbst (1953; 1962) from Banyuls
(South France) and from Brittany (NW France) as C. cf. kieferi
Schafer, 1936 was recorded living as a commensal with polychaetes
(Bretagne) and free-living in the marine interstitial (Banyuls). The
illustrations provided by Herbst differ from the original description
by Schafer (1936) in an important character for the taxonomy of the
genus, the relative length of the female leg 5 exopodal spines. This
discrepancy was already noted by Lotufo (1994) when he presented
the differential diagnosis of C. yutimaete Lotufo in comparison to C.
kieferi. As the female leg 5 of C. cf. kieferi figured by Herbst (1953;
1962) is identical to that of C. esilis, we here consider Herbst’s
material as belonging to C. esilis.

The distribution of Cyclopina esilis thus encompasses the littoral
zone from the Black Sea to the western approaches of the English
Channel; a distribution equivalent to the Mediterranean and
Lusitanian provinces of classical marine biogeography (Ekman,
1953).

Family CYCLOPIDAE Dana, 1846
Subfamily HALICYCLOPINAE Kiefer, 1927
Genus Neocyclops Gurney, 1927

Neocyclops (Protoneocyclops) mediterraneus (Kiefer,
1960)

(Figs 5-7)

Pareuryte mediterranea: Kiefer (1960).
Neocyclops remanei mediterraneus: Pesce & Galassi (1987)

MATERIAL EXAMINED. Cova ‘C’ de Cala Varques (Manacor). UTM
coordinates: 525.27; 4372.19. Topography in Trias & Mir (1977):
Two adult males (one not preserved) and 2 copepodids (one not
preserved) (BMNH 1995. 1329-1330). Collected by authors, 29
March 1995.

ADULT MALE. Body (Fig. 5A) cyclopiform, up to 0.58 mm long,
colourless. Nauplius eye absent. Prosome about 1.4 times as long as
urosome, 5-segmented, first pedigerous somite completely con-
cealed by carapace-like, posterior extension of cephalosome. Rostrum
(Fig. 5B) triangular in frontal view. Urosome 6-segmented, robust.
Fifth pedigerous somite with pointed posterolateral angles; entire
hyaline frill adorning posterodorsal margin of somite. Genital somite
(Fig. 5C) slightly expanded laterally, with ventrolateral fold each
side of somite at about one-third distance from posterior margin;
folds slightly projecting dorsally. Paired gonopores opening ventrally,
each covered by opercular flap derived from sixth leg; flaps each
armed with 1 inner flanged spine and 2 outer plumose setae.
Abdominal somites | to 3 subequal, with posterior margins adorned
with entire hyaline frill. Anal somite bearing operculum dorsally at
about midlength; operculum ornamented with serrate hyaline frill; 4
rows of transverse setules adorning sides of anal cleft; posterolateral
margins of somite bearing serrate hyaline frill. Caudal rami 2.6
times as long as wide, inserted widely separate from each other;
secondary ornamentation of pores and tiny spinules distributed as
figured; armature consisting of 7 setae; seta I reduced, tiny, im-
planted ventrolaterally about one-third of distance along ramus; seta
Il implanted dorsolaterally at about three-quarters of distance along
ramus.

Antennules (Fig. SE) 16-segmented, not extending beyond poste-
rior margin of prosome, symmetrical, digeniculate (Fig. 5A).

OO ——————

CYCLOPOIDS FROM LITTORAL CAVES

: 7 el
k
rong {

Uv
(ran
\

89

Fig. 5. Neocyclops (Protoneocyclops) mediterraneus (Kiefer, 1960), adult male. A, body, dorsal; B, detail of rostral plate; C, genital somite, ventral; D,

anal somite and caudal rami, dorsal; E, antennule; F, fifth leg.

Geniculations between segments homologous with ancestral seg-
ments XV and XVI (10 and 11), and between XX and XXI (14 and
15). Segment 10 cup-shaped, forming sheath around proximal half
of segment 11. Segmental fusion pattern and armature as follows:
segment | (corresponding to fused ancestral segments I toV), 8 setae
+ 3 aesthetascs; segment 2 (partially fused ancestral segments VI and
VII), 4 setae; segment 3 (VIII), 2 setae; segment 4 (IX), 2 setae +

aesthetasc; segments 5 to 8 (X to XIII), 2 setae each; segment 9
(XIV), 2 setae + aesthetasc; segments 10 and 11 (XV and XVI), 2
setae each; segment 12 (XVII), 2 setose spines; segment 13 (XVIII),
1 setose spine, 1 seta + aesthetasc; segment 14 (fused segments XIX
and XX), | modified flattened spine and 3 setae; segment 15
(partially fused segments XXI and XXII), 2 modified flattened
spines, | seta + aesthetasc; segment 16 (fused segments XXIII to

90

D. JAUME AND G.A. BOXSHALL

Fig. 6. Neocyclops (Protoneocyclops) mediterraneus (Kiefer, 1960), adult male. A, antenna; B, labrum, ventral; C, mandible; D, maxillule; E, maxilla; F,

maxilliped.

XXVIII), 11 + 2 aesthetascs.

Antenna (Fig. 6A) well developed, 5-segmented. Coxa and basis
separate, coxa small, unarmed. Basis with 2 distal setae on inner
margin and long distal seta, representing exopod, on outer margin.
First endopod segment with seta inserted midway along inner mar-
gin. Second endopod segment with 2 lateral and 3 distal setae along
inner margin; outer margin covered by patch of setules. Third
endopod segment with 7 unequal setae on tip; outer margin adorned
with 2 patches of setules, as figured.

Labrum (Fig. 6B) with laterally serrate distal margin and row of 9
rounded teeth midway along margin; paired transverse rows of long

/

spinules located subdistally on anterior surface of labrum.

Mandible (Fig. 6C) with coxal gnathobase armed with 9 sharp,
unequal teeth, 2 dorsal setae, and 1 naked setiform element located
between third and fourth ventralmost teeth; inner dorsal seta with
long spinules along one side; outer dorsal seta longer, with short
spinules on both sides; transverse row of 7 long spinules disposed
subdistally on cutting blade. Mandibular palp reduced to knob
bearing 3 unequal setae.

Maxillule (Fig. 6D) with well developed praecoxal arthrite; arma-
ture consisting of 3 stout spines, | tiny spine and 3 slender setae
proximally, and distal lobe armed with 4 thick, denticulate spines; 2

CYCLOPOIDS FROM LITTORAL CAVES

i) | Oameic 7
sss

91

Fig. 7. Neocyclops (Protoneocyclops) mediterraneus (Kiefer, 1960), adult male swimming legs, posterior view. A, leg 1; B, leg 2; C, leg 3; D, leg 4.

patches of tiny denticles on segment, as figured. Palp comprising
coxobasis with 1 spinulate spine and 2 setae distally and | seta
(representing exopod) implanted on outer margin, and 1-segmented
endopod bearing 3 setae (obscured in Fig. 6D).

Maxilla (Fig. 6E) 4-segmented, powerfully developed. Praecoxa
and coxa separate. Praecoxa with single, distal endite armed with 2
elements. Proximal coxal endite represented by single seta; distal
coxal endite discrete, armed with 1 spine fused to endite and
ornamented with 2 strong spinules, and | pectinate spine. Basis with
endite bearing 2 stout pectinate elements, one fused to segment, plus

reduced pinnate seta. Endopod 1-segmented, bearing 3 stout pecti-
nate elements plus 2 reduced, unequal setae.

Maxilliped (Fig. 6F) somewhat reduced in size, 4-segmented.
Syncoxa bearing 2 weakly developed endites with spine formula
2,1. Basis with 2 distal setae on inner margin; secondary ornamen-
tation of spinules and setules on segment as figured. Endopod
2-segmented, setal formula 2,3. Ornamentation on spines and setae
of maxilliped as figured; setae on distal endopodal segment naked.

Swimming legs | to 4 (Fig. 7) biramous, both rami 3-segmented,
except leg 4 with 2-segmented endopod; distal endopodal segment

92

subdivided by posterior surface suture marking plane of fusion
between second and third segments. Legs subequal in size except
first somewhat reduced. Intercoxal sclerites lacking ornamentation.
Legs richly ornamented with spinules, setules and denticles, as
figured. Armature as follows:

Coxa Basis Exopod Endopod
Leg | 0-1 1-I I-1;I-1;0,1,4 0-1;0—2;L,1+1,3
Leg 2 0-1 1-0 I-1;I-1;111,15 0-1;0-2:L 11,3
Leg 3 0-1 1-0 I-1;1-1;0L,1,5 0-1;0—2;1, 11,3
Leg 4 0-1 1-0 L1;-1;0LL1V 0-1; 11, 1+1

Spines on legs 1 and 2 adorned with spinules, those on leg 3
flanged with serrate hyaline frill. Outer spines on exopod and outer
and distal spines on endopod of leg 4 ornamented with serrate
hyaline frill; inner margin setae on both rami modified, spine-like,
ornamented with short pinnules proximally and serrate membrane
distally.

Fifth legs (Fig. 5F) 4-segmented, joined by smooth intercoxal
sclerite. Coxa and basis separate, coxa unarmed, basis bearing
plumose seta on outer margin. First exopodal segment elongate,
about as long as coxa and basis combined, outer margin with
subdistal spine flanged with serrated hyaline frill; spinous process
just anterior to insertion point of spine; flanged spine longer than
segment; inner margin of segment bearing | distal spine adorned
with sparse setules and about as long as segment. Distal margin of
second exopodal segment bearing | seta flanked by 2 spines flanged
with serrate hyaline frill; spinous process just proximal to insertion
point of outer spine; outer spine slightly longer than inner, and
longer than first exopod segment; inner spine about as long as first
endopod segment; seta shorter than spines. Secondary ornamenta-
tion on fifth leg segments as figured.

REMARKS. The genus Neocyclops Gurney, 1927 contains 15 spe-
cies distributed in coastal waters of the Northeast and Tropical
Atlantic (including the Caribbean), the Mediterranean, the Black
and Red Seas, the Indian Ocean, as well as the Pacific (Papua New
Guinea) (Petkovski, 1986; Fiers, 1986; Pesce & Galassi, 1993;
Lotufo & Rocha, 1993; Rocha, 1995). Petkovski (1986) has split the
genus into two subgenera according to the number of exopodal
segments of the male fifth legs. The subgenus Neocyclops, charac-
terized by a 3-segmented male leg 5, embraces the following species:
N. medius Herbst, 1955, N. vicinus (Herbst, 1955), N. affinis (Plesa,
1961), N. salinarum (Gurney, 1927) and N. remanei (Herbst, 1952).

The subgenus Protoneocyclops, with 4-segmented male fifth legs,
comprises P. stocki Pesce, 1985, P. geltrudeae Pesce & Galassi,
1993, P. papuensis Fiers, 1986, P. mediterraneus (Kiefer, 1960), P
herbsti Petkovski, 1986, P. wellsi Petkovski, 1986 and P. ferrarii
Rocha, 1995. This subgenus displays the so-called full Tethyan
pattern of distribution (Stock, 1993), i.e., circum-tropical in the
entire region of the former Tethys Sea.

Three other species, viz. N. improvisus Plesa, 1973 from Cuba,
and N. magnus (Sewell, 1949) and N. parvus (Sewell, 1949) from
islands in the Indian Ocean, cannot be assigned to either subgenus as
their males are unknown.

Three representatives of the genus are known so far from the
Mediterranean region. Neocyclops (N.) salinarum, originally de-
scribed from the Suez Canal, was reported also from the Camargue
(South France) and the Sirbonian lagoon (Mediteranean coast of
Sinai) (Gurney, 1927a; 1927b;Aguesse & Dussart, 1956; Por, 1973).
As Petkovski (1986) pointed out, the identity of the French popula-
tion needs to be confirmed. Similarly the single copepodid from the

D. JAUME AND G.A. BOXSHALL

Andaman Islands (Indian Ocean), assigned by Sewell (1949) to this
species, should be reexamined. Neocyclops (N.) vicinus, a species
distributed along the coasts of Brazil and the Lesser Antilles (Pesce
& Galassi, 1993; Lotufo & Rocha, 1993), has been also reported
from the Black Sea (as Eurycyclops remanei vicinus) by Plesa
(1963) and Monchenko (1975). As pointed out by Lotufo & Rocha
(1993), this record is dubious since their material seems more
closely related to N. (N.) remanei than to N. (N,) vicinus.

The single representative of the subgenus Protoneocyclops in
Mediterranean waters is Neocyclops (P.) mediterraneus, originally
described by Kiefer (1960) as Pareuryte mediterranea from an
anchihaline cave on Menorca (Balearic Islands). Later, Pesce &
Galassi (1987) reported it from an anchihaline cave in Southern
Italy. Plesa (1981) cited the same species from Cuba, but this record
has been reassigned by Petkovski (1986) to N. (N.) stocki, a taxon
widespread in the Caribbean region (Pesce & Galassi, 1993).

The Neocyclops from Mallorca has been identified on the basis of
the 4-segmented condition of the male fifth legs and the relative
lengths of the armature elements on this leg. Mallorca is also close
to the type-locality of the species (Menorca). Other characters could
not be checked against Kiefer’s (1960) original description since this
contained only 5 drawings (viz. female anal somite and caudal rami,
distal segment of endopod of female leg 4; fifth leg of both sexes, and
genital operculum of male). In addition, Kiefer did not designate
types for the species. Pesce & Galassi (1987) had only 2 females at
their disposal for their supplementary description.

A differential diagnosis of Neocyclops (Protoneocyclops)
mediterraneus (Kiefer, 1960) can be constructed based on charac-
ters of the male fifth leg. It differs from N. (P.) geltrudeae Pesce &
Galassi (1993) from Curacao (Antilles) in the number of armature
elements on the distal segment (3, compared to 4 inN. (P.) geltrudeae).
Differences from N. (P.) papuensis Fiers, 1986 from New Guinea
and N. (P.) ferrarii Rocha, 1995 from Brazil involve the relative
lengths of the spines on the distal segment (the inner spine is clearly
longer than the outer in both these species whereas in N. (P.)
mediterraneus the outer spine is subsimilar, slightly longer than the
inner). Differences from N. (P.) herbsti Petkovski (1986) from the
Red Sea, and N. (P.) stocki Pesce, 1985 from the Caribbean, are
based on the relative lengths of the flanged spines on the 2 distal
segments of leg 5 (these are clearly shorter than the first exopodal
segment whereas in N. (P.) mediterraneus they are longer than the
segment). In addition, in N. (P.) herbsti the armature element on the
inner margin of the first exopodal segment is a plumose seta,
whereas in WN. (P.) mediterraneus it is a thick spine. Differences from
N. (P.) wellsi Petkovski (1986) from Mozambique lie only in the
nature of the armature element on the inner margin of the first
exopodal segment, which is also a seta in this species instead of a
thick spine.

Subfamily EURYTEINAE Monchenko, 1975
Genus Euryte Philippi, 1843

Euryte longicauda Philippi, 1843 emend. Giesbrecht,
1900

(Figs 8-11)

MATERIAL EXAMINED. Cova de na Barxa (Capdepera). UTM coor-
dinates: 539.30; 4393.10. Topography in Andrews et al. (1989): Two
adult females, 1 adult male, and 1 copepodid (BMNH 1995. 1323—
1326). Collected by authors, 3 April 1995. — Cova de na Mitjana
(Capdepera): 19 adult males, 7 adult females, and 5

CYCLOPOIDS FROM LITTORAL CAVES 93

Fig. 8. Euryte longicauda Philippi, 1843, adult male. A, body, dorsal; B, lateral; C, detail of rostral plate; D, genital and first abdominal somites, ventral;
E, same, lateral; F, anal somite and caudal rami, dorsal; G, antennule; H, fifth leg.

copepodids (BMNH 1995. 1313-1322). Collected by authors, 1 (BMNH 1995. 1327). Collected by D. Jaume, 25 May 1994.
April 1995. — Es Secret des Moix (Manacor). Coordinates: 523.69; ADULT MALE. Body (Figs 8A, B) cyclopiform, up to 0.61 mmlong,
4365.53. Topography in Ginés et al. (1975): One adult female body surface completely covered by tiny cuticular granulations.

94

D. JAUME AND G.A. BOXSHALL

Fig. 9. Euryte longicauda Philippi, 1843, adult male. A, antenna; B, mandible; C, maxillule praecoxal arthrite; D, maxillulary palp; E, maxilla; F,

maxilliped.

Prosome about 1.4 times longer than urosome, comprising
cephalosome plus 4 free pedigerous somites; first pedigerous
somite completely concealed beneath posterior extension of
cephalosome, with lateral margins weakly sclerotized; second to
fourth somites with evenly rounded posterolateral corners. Ros-
trum (Fig. 8C) fused at base, well developed, subtriangular in
frontal view. Urosome 6-segmented; first abdominal somite with
pointed posterolateral angles; entire hyaline frill adorning
posterodorsal margin. Genital somite (Figs 8D,E) symmetrical,
laterally expanded, with entire hyaline frill around posterodorsal
margin; pair of gonopores opening ventrally at posterior border of
somite; opercular flaps each armed with 1 inner flanged spine plus
2 outer setae. Third to fifth urosome somites subequal, narrower
than genital somite, with entire hyaline frill adorning posterior
margin. Anal somite (Fig. 8F) about same size as preceding
somites; smooth anal operculum present at one third of distance
along somite; serrate hyaline frill around posterolateral margins of

somite. Caudal rami (Fig. 8F) of variable length, from 4.4 to 6.4
times longer than wide, slightly divergent; distal part slightly
wider; armature consisting of 6 setae; seta II located subdistally.
Antennules (Fig. 8G) 16-segmented, symmetrical, digeniculate
with geniculations between segments homologous with ancestral
segments XV and XVI (10 and 11), and segments XX and XXI (14
and 15). Segment 10 cup-shaped, forming sheath around proximal
half of segment 11. Segmental fusion pattern and armature as
follows: Segment | (corresponding to fused ancestral segments I to
V), 8 setae + 3 aesthetascs; segment 2 (corresponding to fused
ancestral segments VI and VII), 4 setae; segment 3 (VIII), 2 setae;
segment 4 (IX), 2 + aesthetasc; segments 5 to 8 (X to XIII), 2 setae
each; segment 9 (XIV), 2 + aesthetasc; segment 10 (XV), 2 setae;
segment 11 (XVI), 2 + aesthetasc; segment 12 (XVII), 1 short
denticulate spine and | seta; segment 13 (XVIII), 1 short denticulate
spine, | seta + aesthetasc; segment 14 (fused ancestral segments
XIX and XX), | short denticulate spine, 1 modified flattened spine,

CYCLOPOIDS FROM LITTORAL CAVES

95

Fig. 10. Euryte longicauda Philippi, 1843, adult male swimming legs, posterior view. A, leg 1; B, leg 2; C, leg 3; D, leg 4.

1 seta + minute aesthetasc; segment 15 (fused ancestral segments
XXI to XXIII), 2 modified flattened spines, 1 seta + aesthetasc;
segment 16 (fused segments XXIV to XXVIII), 11 setae + 2
aesthetascs.

Antenna (Fig. 9A) 4-segmented. First segment representing par-
tially fused coxa and basis, armed with 2 inner basal setae distally,
and | outer seta representing exopod; patch of setules present
midway along outer margin of segment. Endopod 3-segmented; first
segment about as long as coxa and basis combined, armed with 1
seta at three-quarters of distance along inner margin; outer margin

ornamented with setules. Segments 2 and 3 subsimilar in size, each
about half length of segment 1. Segment 2 armed with 2 lateral and
3 distal setae, one of latter (seta VIII in scheme of Boxshall &
Evstigneeva, 1994) claw-like, along inner margin. Segment 3 armed
with 7 distal setae, one claw-like; outer margin with 2 rows of
setules, as figured.

Mandible (Fig. 9B) with large coxal gnathobase bearing 11
unequal, sharp blades, plus 2 dorsal spines; outer dorsal spine
spinulate; transverse row of 6 thin spinules located adjacent to
cutting edge. Palp reduced to knob bearing 3 setae.

96

Maxillule with praecoxal arthrite (Fig. 9C) well developed, armed
distally with 4 stout, denticulate spines, plus 6 more proximal
elements, ranging from a tiny seta to a thick denticulate spine. Palp
(Fig. 9D) comprising coxobasis with medial gnathobase-like struc-
ture and minute endopodal segment bearing 2 setae; distal margin of
coxobasal gnathobase provided with 9 irregular blades; coxobasis
with 2 setae located subapically on dorsal margin and single seta,
representing exopod, located proximally on distal surface.

Maxilla (Fig. 9E) well developed, 4-segmented. Praecoxa and
coxa incompletely separate. Praecoxa naked, lacking endites. Coxa
with proximal endite represented by single seta; distal endite power-
fully developed, bearing 2 stout, spinulate spines, proximal spine
bearing single, conspicuous strong spinule on outer margin and row
of thinner spinules on inner margin. Basis with endite bearing 3
unequal, claw-like setae. Endopod 1-segmented, armed with total of
3 stout spine-like setae, 1 naked seta and 1 very reduced seta.

Maxilliped (Fig. 9F) 5-segmented, prehensile. Syncoxa bearing 2
weakly developed endites provided with single seta each. Basis with
inner margin covered by patch of setules and single seta positioned
distally. Endopod 3-segmented, first segment short, unarmed; sec-
ond segment elongate, inner margin covered by patch of setules,
armed with 2 setae laterally; small distal segment with 2 stout,
curved claws plus 2 accessory setae.

Swimming legs 1 to 4 (Fig. 10) biramous, both rami 3-segmented.
Legs subequal in size except first somewhat smaller. Intercoxal
sclerites lacking ornamentation and getting progressively narrower
from legs 1 to 4. All spines on segments flanged bilaterally with
serrate hyaline frill except distalmost spine on exopod of leg 1,
which is flanged with frill on outer side only, inner side adorned with
row of setules. Secondary ornamentation and pore pattern on seg-
ments as figured; pores on coxa and basis possibly overlooked.
Armature as follows:

Coxa Basis Exopod Endopod
Leg | 0-1 1-I I-1;1-1;01,1,4 0-1;0—2;I-I-I1
Leg 2 0-1 1-0 I-1;-1;01,1.1V+1 0-1;0-2;I-I-II
Leg 3 0-1 1-0 ISA EY 0—1;0—2;I-II-Il
Leg 4 0-1 1-0 I-1;-1;0,1,V 0-1;0-IL;I-0-II

Fifth legs (Fig. 8H) uniramous, 3-segmented, joined by smooth
intercoxal sclerite. Coxa and basis separate, former naked, latter
with single seta on outer margin. Distal segment (exopod) elongate,
about 2.5 times as long as wide; armature consisting of flanged spine
as long as segment located two-thirds of distance along outer
margin, plus 2 flanged spines and single seta on distal margin; distal
seta shorter than both spines and segment itself; distal spines located
either side of seta, flanged, both clearly longer than segment, inner
longer, about 1.5 times as long as segment. Secondary ornamenta-
tion of spinules present on outer margin of exopod of some
individuals, similar to that figured on female leg 5 (Fig. 11E), not
present in figured specimen (Fig. 8H).

ADULT FEMALE. Body (Figs 11A, B) up to 0.74 mm long, resem-
bling male. Urosome 5-segmented; genital and first abdominal
somites partially fused to form genital double-somite. Genital dou-
ble-somite (Fig. 11C) symmetrical, subdivided dorsally by partial
suture line; single copulatory pore opening mid-ventrally about
one-third of distance along somite, connected via copulatory duct
to fused seminal receptacles. Paired gonopores located laterally;
gonopores covered by opercula, each consisting of lobe projecting
dorsally bearing 2 setae and | tiny spine. Tapering soft lobe point-
ing posteriorly located at both sides of somite just behind

D. JAUME AND G.A. BOXSHALL

operculum. Entire hyaline frill present along posterior margin of
somite.

Antennules (Fig. 11D) 21-segmented, not extending beyond pos-
terior margin of cephalosome (Figs 11A, B), symmetrical. Segmental
fusion pattern and armature as follows: Segment | (corresponding to
fused ancestral segments I to V), 8 setae; segment 2 (fused ancestral
segments VI and VII), 4 setae; segments 3 to 9 (VIII to XIV), 2 setae
each; segments 10 to 13 (XV to XVIII), 1 seta each; segment 14
(XIX), naked; segment 15 (XX), 1 seta; segment 16 (XXI), 1 seta +
aesthetasc; segment 17 (XXII), naked; segment 18 (XXIII), 1 seta;
segment 19 (XXIV), 2 setae; segment 20 (XXV), 2 + aesthetasc;
segment 21 (fused XXVI to XXVIII), 7 + aesthetasc.

Segmentation and setation of other cephalosomic appendages and
swimming legs | to 4 as in male.

Fifth legs (Fig. 11E) resembling those of male, but with shorter
exopod, about twice as long as wide; inner distal spine almost twice
as long as segment; spine on outer margin clearly longer than
segment. Secondary ornamentation of spinules on outer margin of
exopod not discernible in some individuals.

REMARKS. The genus Euryte typically contains shallow water
hyperbenthic species, although Brady (1910) reported the genus
from depths of 320 m in the Antarctic and some species have been
found living in the interstices of coarse sand, or in association with
seaweed or corals. Ten species are currently recognized, distributed
worldwide (Gurney, 1927b; Sewell, 1949; Herbst, 1989; Humes,
1991; 1992), with the possible exception of the Pacific coast of
South America. Apart from the original contributions by Giesbrecht
(1900) and Sars (1913-1918), new species have been described
mainly on the basis of a biometric analysis of characters that have
otherwise proved to exhibit high intra-populational variability (such
as the relative legth of caudal rami), or that may vary significantly in
their measurements simply according to the precise angle of obser-
vation (such as the relative length of the armature elements on the
distal segment of the endopod of leg 4). Such characters are widely
used in the two identification keys available for the genus (Vervoort,
1964; Herbst, 1989), and their use has resulted in the false impres-
sion of cosmopolitanism of some taxa (viz. E. longicauda and E.
robusta Giesbrecht, 1900; see Kiefer (1929) and Sewell (1949)).

The type material for most species of Euryte is no longer extant.
This hampers the necessary revision of the genus, that could permit
the critical reevaluation of all those taxa established on the basis of
variable characters.

Using material from the type locality of both species (the Gulf of
Naples), Giesbrecht (1900) differentiated E. /ongicauda Philippi,
1843 from E. robusta Giesbrecht, 1900 mainly by the proportions of
the caudal rami and by details of the armature of the male antennule.
The proportions of the caudal rami of the Mallorcan population
overlap the characteristic values for both species given by Giesbrecht
(1900). The armature of the male antennule, however, corresponds
to that of E. longicauda: the cup-shaped segment 10 carries 2 slender |
setae, whereas in E. robusta it carries a characteristic robust, S- |
shaped spine plus a seta. On this basis we have assigned the Euryte |
from the Mallorcan caves to E. longicauda. .

The differential diagnosis separating E. longicauda from Mallorca |
from E. robusta can be completed as follows (see the detailed |
illustrations of the latter species in Huys & Boxshall, 1991): in E. |
longicauda the proximal spine on the distal coxal endite of the
maxilla of both sexes is armed with a single, strong spinule on one
side and a row of thinner spinules on the other side; in E. robusta
both sides are armed with thin spinules.Additionally, inE. longicauda
there is a transverse dorsal suture midway along the female genital
double-somite that seems to be absent in E. robusta.

CYCLOPOIDS FROM LITTORAL CAVES

97

| Fig. 11. Euryte longicauda Philippi, 1843, adult female. A, body, dorsal; B, lateral; C, genital double-somite, lateral; D, antennule; E, fifth leg.

The distribution of E. longicauda apparently encompasses all
European coasts from the Black Sea to the Arctic Ocean (Franz-
Joseph Land) and the East coast of Greenland (Giesbrecht, 1900;
Herbst, 1989) but many of the records of this species are accompa-
nied by inadequate descriptions, if any. Geographically remote
records from outside the European region, such as those of Gurney

(1927b) from the Suez Canal and Samoa, or those of Thomson
(1882) (as Thorellia brunnea var. antarctica) from New Zealand,
require verification.

The body size of the Euryte longicauda from Mallorca falls in the
range characteristic of the variety E. longicauda var. minor Scott,
1905, which was elevated, rather inconsistently, to full specific

98

status by Sars (1919-1921). This variety is supposed to inhabit
deeper waters and never to occur in the littoral zone (Sars, 1913—
1918; 1919-1921).

According to Sars (1913-1918) E. longicauda carries only modi-
fied flanged spines on the inner margin of the third exopodal
segment of leg 2. In our material the proximalmost element on the
inner margin of this segment is a plumose seta (Fig. 10B). However,
this may be an observational error by Sars since material of E.
longicauda from Raunefjorden in Norway (BMNH 1986.387) and
from Scotland (BMNH 1951.8.10.587) in the collections of the
Natural History Museum possesses a plumose seta in this position,
as in the Mallorcan material.

REVIEW OF EURYTE SPECIES

The eight remaining species of Euryte are briefly reviewed here, in
order to facilitate the identification of representatives of this prob-
lematic genus. The review is essentially comparative and emphasises
the most robust and reliable characters available in published de-
scriptions.

E. curticornis Sars, 1913 is characterised by short, 21-segmented
female antennules and the shortened third segment of the maxilliped;
the curved distal claws on this appendage are also reduced in size
and subsimilar in length. These features contrast with the maxilliped
of E. longicauda, which is provided with an elongate third segment
and with long, unequal distal claws. The distal spines on the third
segment of endopod of leg 1 are clearly unequal in length in E.
curticornis, whereas in E. longicauda they are about equal.

E. longicauda can be distinguished from E. grata Herbst, 1989
and E. verecunda Humes, 1992 by some features of the maxilla and
maxilliped. In E. verecunda, the proximal spine on the distal coxal
endite of maxilla is adorned on both sides with slender spinules. On
the maxilliped, the armature element on the proximal syncoxal
endite is a seta in E. longicauda, whereas in E. grata and E.
verecunda this endite is represented by a stout spine. E. verecunda
differs additionally in the setose condition of the armature elements
on the inner margin of the second endopodal segment of leg 4; these
elements are flanged spines in E. longicauda. The generic placement
of E. verecunda needs verification since, according to Humes (1992),
this species displays a 2-segmented condition of leg 5. This is a
characteristic of the genus Ancheuryte Herbst, 1989, whereas in
Euryte leg 5 is 3-segmented in both sexes.

In E. pseudorobusta Vervoort, 1964 two distal setae are present in
the outer margin of the antennary coxobasis, whereas there is only |
seta in E. longicauda. The proximal spine on the distal coxal endite
of maxilla has a different armature in the two species, with a row of
setules along each side in E. pseudorobusta. Finally, the caudal rami
of E. pseudorobusta are short, about as long as the anal segment, and
differ significantly from the elongate caudal rami of E. longicauda.

Two other species, each described from a single female from the
Addu Atoll (Maldives), viz. E. brevicauda Sewell, 1949 and E.
sewelli Vervoort, 1964 (= ‘Euryte sp. of Sewell, 1949) also differ
from E. longicauda in their very short caudal rami. The status of E.
sewelli Vervoort, 1964 as a distinct species from E. brevicauda is
equivocal (Vervoort, 1964; Sewell 1949). The main difference be-
tween them is the apparently 18-segmented female antennule in the
former species. Unfortunately, Sewell’s (1949) original material is
not preserved, thus precluding verification. However, if Sewell’s
illustrations are accurate, the 18-segmented antennule, combined
with the absence of the inner seta on the proximal segment of exopod
of leg 1, can be used as diagnostic characters of this taxon.

D. JAUME AND G.A. BOXSHALL

E. longicauda differs from E. bellatula Humes, 1991 in the nature
of the two armature elements on the inner margin of the second
endopodal segment of leg 4; these are flanged spines in the former
species, whereas in the latter they are setae. E. bellatula also has the
proximal spine on the distal coxal endite of maxilla armed with a row
of thin spinules on both sides.As commented above for E. verecunda,
the generic placement of E. bellatula must be confirmed due to the
apparently 2-segmented condition of the leg 5. The association with
corals of the two taxa described by Humes is similar to the life-style
of Ancheuryte, a closely related genus characterized by its 2-seg-
mented leg S.

The status of E. similis Scott, 1912, originally described from the
South Orkneys and never found since, is debatable. Scott pointed out
its similarity to E. robusta, and that it appeared *. . . to differ in one
or two minor points, such as in the armature of the first and fourth
pairs of thoracic legs and in the proportional lengths of the abdomi-
nal segments’ (Scott, 1912). The differences in the armature of the
swimming legs mentioned by Scott in the text do not correspond
with his figures. Also, as Sewell (1949) already pointed out, it seems
certain that Scott had confused the legs so that his second leg is in
reality the fourth, and his fourth leg is either the second or third. In
fact, the original description is very superficial and does not permit
any conclusion other than that the taxon belongs to Euryte. The only
apparent diagnostic features displayed by this taxon could be the
lack of an inner seta on both the first endopodal and first exopodal
segments of leg 4 (Scott’s leg 2). This is unreliable, however, since
the number of armature elements on the swimming legs is a very
conservative character at the generic level in the Cyclopidae. In our
opinion, given the lack of type material, this taxon should be
considered species inquirendum.

ACKNOWLEDGEMENTS. We want to thank J. Pons-Moya and G. Pons their
support during fieldwork, and Dr Rony Huys and Prof Carlos Eduardo
Falavigna da Rocha for their detailed comments and improvements to the
manuscript. Contribution to project DGICYT PB91—0055 and EC Training
Research Contract ERBCHBICT941 306.

REFERENCES

Aguesse P.C. & Dussart, B.H. 1956. Sur quelques crustacés de Camargue et leur
écologie. Vie et Milieu, 7: 481-520.

Andrews, J.N., Ginés, A., Ginés, J., Pons-Moya, J., Smart, P.L. & Trias, M. 1989.
Noves dades sobre el jaciment paleontologic de la Cova de na Barxa (Capdepera).
Endins, 14/15: 17-26.

Boxshall, G.A. & Eystigneeva, T.D. 1994. The evolution of species flocks of copepods
in Lake Baikal: a preliminary analysis. Archiv fiir Hydrobiologie Beiheft Ergebnisse
der Limnologie, 44: 235-245.

Brady, G.S. 1910. Die marinen Copepoden der Deutschen Siidpolar Expedition 1901—
1903. I. Uber die Copepoden der Stamme Harpacticoida, Cyclopoida, Notodelphyoida
und Caligoida. Deutsche Siidpolar-Expedition, 1901-1903, 11 (Zool. 3): 497-593,
pls. 52-63.

Brian, A. 1938. Description d'une nouvelle espece de copépode cyclopoide du genre
Cyclopina. Bulletin de la Société zoologique de France, 63: 13-18.

Ekman, S. 1953. Zoogeography of the Sea. 417 pp. Sidgwick and Jackson Ltd, London.

Fiers, F. 1986. New and interesting copepods (Crustacea, Copepoda) from brackish
waters of Laing Island (Northern Papua New Guinea). Bulletin de |’ Institut royal des
Sciences naturelles de Belgique (Biologie), 56: 99-120.

Fosshagen, A. & Iliffe, T.M. 1985. Two new genera of Calanoida and a new order of
Copepoda, Platycopioida, from marine caves on Bermuda. Sarsia, 70: 345-358.
Giesbrecht, W. 1900. Mittheilungen iiber Copepoden. 12. Die litoralen Cyclopiden des
Golfes von Neapel. Mittheilungen aus der zoologischen Station zu Neapel, 14: 39-

82, pls. 1-5.

Ginés, A., Ginés, J. & Pons-Moya, J. 1975. Nuevas aportaciones al conocimiento
morfologico y cronolégico de las cavernas costeras mallorquinas. Speleon,
Monografia 1: 49-56.

CYCLOPOIDS FROM LITTORAL CAVES

Gurney, R. 1927a. Zoological results of the Cambridge Expedition to the Suez Canal,
1924. IX. Report on the Crustacea Copepoda of Brine-Pools at Kabret. Transactions
of the Zoological Society of London, 22: 173-177.

1927b. Zoological results of the Cambridge Expedition to the Suez Canal, 1924.
XXIII. Report on the Crustacea: Copepoda (littoral and semi-parasitic). Transac-
tions of the Zoological Society of London, 22: 451-577.

Herbst, H.V. 1953. Weitere Cyclopoida Gnathostoma (Crustacea Copepoda) des
Kiistengrundwassers. Kieler Meeresforschungen, 9: 257-270.

— 1962. Marine Cyclopoida Gnathostoma (Copepoda) von der Bretagne-kiiste als
kommensalen von Polychaeten. Crustaceana, 4: 191-206.

— 1982. Drei marine Cyclopoida Gnathostoma (Crustacea: Copepoda) aus dem
nordamerikanischen Kiistenbereich. Gewdsser und Abwdsser, 68/69: 107-124.
— 1989. Neue marine Cyclopoida Gnathostoma (Crustacea, Copepoda) von Puerto

Rico. Bijdragen tot de Dierkunde, 59: 43-61.

Humes, A.G. 1991. Copepoda associated with the scleractinian coral genus Montipora
in the Indo-Pacific. Proceedings of the Biological Society of Washington, 104: 101—
N29

—— 1992. Euryte verecunda, new species (Copepoda: Cyclopoida), associated with
the coral Porites lobata on the Pacific coast of Panama. Proceedings of the Biological
Society of Washington, 105: 268-274.

Huys, R. & Boxshall, G.A. 1991. Copepod Evolution. 468 pp. The Ray Society,
London.

Jaume, D. & Boxshall, G.A. 1996. A new genus and two new species of cave-dwelling
misophrioid copepods from the Balearic Islands (Mediterranean). Journal of Natu-
ral History, 30: 989-1006.

Kiefer, F. 1929. Crustacea Copepoda. II. Cyclopoida Gnathostoma. Das Tierreich, 53:
1-102.

— 1960. Beitriige zur Copepodenkunde (XX). Zoologischer Anzeiger, 165: 37-45.

Lotufo, G.R. 1994. Cyclopina (Copepoda, Cyclopoida) from Brazilian sandy beaches.
Zoologica Scripta, 23: 147-159.

— & da Rocha, C.E.F. 1993. Neocyclops Gurney from Brazilian sandy beaches
(Copepoda: Cyclopoida). Bijdragen tot de Dierkunde, 63: 163-172.

Monchenko, V.I. 1975. Eurycyclops (Crustacea, Copepoda) in fauna of the Soviet
Union. Dopovidi Akademii Nauk Ukrayinskoi RSR, (B) 1975 (5): 471-477. (in
Ukrainian with Russian and English summaries).

1979. The second finding of Cyclopina esilis Brian (Crustacea, Copepoda) and
redescription of the species. Doklady Akademii Nauk ukrainskoi RSR, (B) 1979 (5):
387-391. (in Ukrainian with Russian and English summaries).

— 1981. Cyclopina oblivia sp. n. (Crustacea, Copepoda) from the interstitial of the
Black Sea. Vestnik Zoologii, 1881 (5): 10-16. (in Russian with English summary).

Pesce, G.L. & Galassi, D.P. 1987. Discovery of the first representative of the genus
Neocyclops Gumey (Copepoda, Halicyclopinae) in groundwater of Italy. Crustaceana,
52: 209-212.

99

1993. The genus Neocyclops Gurney in the West Indies: an update including the
description of Neocyclops (Protoneocyclops) geltrudeae n. sp. (Crustacea, Cope-
poda, Cyclopidae). Bijdragen tot de Dierkunde, 63: 115-120.

Plesa, C. 1963. Etude sur la faune interstitielle littorale de la Mer Noire, III. Résultats
preliminaires des recherches sur la cOte roumaine, avec apercue spécial sur les
Cyclopoides Gnathostomes (Crustacea, Copepoda). Vie et Milieu, 14: 775-814.

1981. Cyclopoides (Crustacea, Copepoda) de Cuba. Résultats des Expéditions
biospéologiques cubano-roumaines a Cuba, 3: 17-34.

Petkovski, T.K. 1986. Zur Taxonomie des genus Neocyclops Gurney, 1927 (Crustacea,
Copepoda, Cyclopoida), Acta Musei macedonici Scientiarum naturalium, 18 (2/
148): 2746.

Por, F.D. 1973. The benthic Copepoda of the Sirbonian Lagoon (Sabkhat el Bardwil).
Cahiers de Biologie marin, 14: 89-107.

Rocha, C.E.F. da & Iliffe, TM. 1991. Speleoithonidae, a new family of Copepoda
(Cyclopoida) from anchialine caves on the Bahama Islands. Sarsia, 76: 167-175.
— 1994. Troglocyclops janstocki, new genus, new species, a very primitive cyclopid
(Copepoda: Cyclopoida) from an anchialine cave in the Bahamas. Hydrobiologia,

292/293: 105-111.

1995. Neocyclops (Protoneocyclops) ferrarii, a new species of cyclopid (Cope-
poda: Cyclopoida) from Belize, with remarks on the morphology of the genus
Neocyclops. Contributions to Zoology, 65: 41-51.

Sars, G.O. 1913-1918. An account of the Crustacea of Norway. VI. Copepoda
Cyclopoida. 225 pp., 118 pls. Bergen Museum.

1919-1921. An account of the Crustacea of Norway. VII. Copepoda Supplement.
121 pp., 76 pls. Bergen Museum.

Schafer, H.W. 1936. Cyclopiniden (Crustacea Copepoda) aus der deutschen Nordsee.
Zoologischer Anzeiger, 113: 167-174.

Scott, T. 1912. The Entomostraca of the Scottish National Antarctic Expedition.
Transactions of the Royal Society of Edinburgh, 18: 521-599, 14 pls.

Sewell, R.B.S. 1949. The littoral and semi parasitic Cyclopoida, the Monstrilloida and
Notodelphyoida. Scientific Reports of the John Murray Expedition, 7: 117-382, |
chart.

Stock, J-H. 1993. Some remarkable distribution patterns in stygobiont Amphipoda.
Journal of Natural History, 27; 807-819.

— lliffe, T.M. & Williams, D. 1986. The concept ‘Anchialine’ reconsidered.
Stygologia, 2: 90-92.

Thomson, G.M. 1882. On the New Zealand Copepoda. Transactions and Proceedings
of the New Zealand Institute, 15: 93-116.

Trias, M. & Mir, F. 1977. Les coves de la zona de C’an Frasquet — Cala Varques.
Endins, 4: 21-42.

Vervoort, W. 1964. Free-living Copepoda from Ifaluk Atoll in the Caroline Islands
with notes on related species. United States National Museum Bulletin, 236: |—
431.

Bull. nat. Hist. Mus. Lond. (Zool.) 62(2): 101-132

Issued 28 November 1996

Studies on the deep-sea Protobranchia
(Bivalvia): the family Neilonellidae and the

family Nuculanidae.

J.A. ALLEN

University Marine Biological Station, Millport, Isle of Cumbrae, Scotland, KA28 OEG

H.L. SANDERS

The Woods Hole Oceanographic Institution, Massachusetts, 02543, USA

CONTENTS

PMN PS SSP ee crs ashe eee ac vars Sadeas oP eSeU cctv snes de cco esuassh insnasvaendedh ansitevacscnapaceriesucscesaesussscucess Gssentsaadszeosssosesscaassunk stvcuavensveoceokuaeamneeh 101

OMEGA [NCU Mrneercse st Mates ete toys 2 dav sasaeen don aiens scarcans cxarvne\ uns eesinaaiscesteananvscstsaesg' tuadana taant¥ivnes seater Ouieuoseinarcer ycedeccenrendsefecnectteie 101

PARAL GUN Gi oTa CITC oi oy oo pe ABP eR ie RE Se ar 9 Nf a ee ete eed Ce a eee ea 102
WNT FLC NOMS (ALIC LES ESY (SEPIESIIZ AML OHO) | ceees catiicccassaces cectresesanc sal sarseereacersers snattes see verceereeeauesttrtemetecccttranssteesemsernre emer 103
INET LOFIG UCARITELIIEIS OLE (LEWC SPECIES) tecans guts dacaaseexsnsordacates os dssucicsvacuusetecssraceaeceeee ovate rr tecescett faeetteneceerstecaseors reso eee Ee 107
INELLOTC ILE CONULCMICN (DAM ISO) levssartsae sce saaeeavncs sap shack da ssaeczaacectetescasstoct te seeea ee meehs eee ae e 108
IN GLPOMICLICNUITOTIA UE WIS PECIES)) 9 cntetesSeedsesevaccsotecreatas overs sucaseeascretoeetonere mae mermereeteas etcetera cenesetitttr me emteecnie teats 108

Sarat aI NVI GUIRAUN Cea setre set cca ewan neas sevadeodivghectuativaestevensteensss ucosascuassasecasteatersccset sachets cest = Saeeias Sen VE caste te hs oat Ene ee 111

Sn etn eae LE AS ae sess oes e crag ec spaicansssansuavaeueh onsvasdadusonsasvadeveceay sone leet ase ee aucnivaiexadte etteeceeevvetaee eek states loeeioas sta aeeee 111
ECCI NCC URAL 2) (EX ANIL OO) fre sete oes ce 5 Se Reps occ esa an ackkda vasanivausasoducaces ote casa deeene NER eT PRCT ee en 111
HECCLCLIGIUAD EFFI (MEM SII CIES) teste sae etas tacay vs coe ihdasusten uses sats <veuaearchceananeaamebenementscesce nes eacherentnarsnces acs tes seep aera tart ae 114
MI NAANLOPSIS GLALICAG\ (UAL MISSI) <.scsncnsenavaccenswasassaccesssoonssutsondesiaicescaceasumteneeusntetecarsereades sxasseesteeannvaceeiasvtaesneeemee eae 116
TPOAGIIODSISCCOMAIGN ALL NOOO) \ccavcrveaveceeseccevgrswesetoss s¥apansaucsaacvevuaasudeptenanatteentawsnetheiavatenveu sone certe cstsctvoreudagrees Gaape nee Seem 119
BUMS EARITAV MING UNNI CLE Ponsrences ese ete rerae <noveceatuit ta cee Svat aa fas sacnaved snsscases vayeeeterenustaarensnca dca tevaewne cacaewenecererteraseokote cater ener meee 120

iia teni tigi ere Grartiak (Chey E213) le eens ete pe cdr Ere Sons Ce eC EP EERE PEE EC ERE cocee cota ORC EESO oP EE CEPT CEES Hee EAM OGE EET CERES Mn occnoceds 120
UN AGS UCEILCANG OMEIIILIALCLLCAN OEAENIIMTO [DMO OAPE) eee c cout dec eck te cae tee eces nn set cee une s oceaeresaeeetuaca Sey dea at ccnes tuaaweve ce nuckesslsdsWiegs ose eecee nae 123
INGLE CUCM ESTIIC (IB OCALCMILG SG). eercttevec et asic ts leveve Sherotcets vassoeusteavescstovinstdarenesneateascuceterecevsvoral Seaver vA tase eetedean ottavee ties <corerast 124
FAROE LEC CACCT FONIIC IIa UO) Al Oil) ae set .anrer ue nc csesthc ON Ge ctssatuasscesa=sseavsvevacedsecnensecanscdsiauas sutuinessesivevetrwverionarsvastectvassine mecemeeness 125
EERO CLC CAIN CUALSC ELA OL ATIN CM NOON) aater ves erteeectacrans senate ties ces nice Sup eve cueciasi enn nsbaedoue vances tase dusvanacuseosesee -undecatteasunvemerartart Seems 127
Lah O DALCE CATIA GUSERICULG (IEW SPC CLES) Iiax va tteceseccacceetsveeseave scons: sceesecasrossssetcnabvacvoneshardeencetucsonesnreecet ssesseusteessnensaukedcncesteodeaten de 128

TBD USTaIT SLMS eee «cedar se stv ategs out ate Adee tn wees adeaeancuaeuss vas cadvdesev les ceaesacseacisscsicsureaescasesanaccscascscedaacinsesddasvsceodueavaseleiapareaiestsbesveaueaies 130

DESL CE Stee gee OO a a II a ue tees van ints oid cvaoma soe oteweiinsaessiessnsdaciin ss (cleaWctviawnasanee teecececesuteviasceneeeeeetaceed 131

SYNoPSIS. The morphology and distribution of four deep-water protobranch species of the family Neilonellidae and ten deep-

water protobranch species of the family Nuculanidae are described. These include four new species. The evolution of the

nuculanoid siphonate form is discussed.

INTRODUCTION

This is the ninth paper in a series on the deep-sea species of
Protobranchia of the Atlantic. While a few undescribed species of
families reported upon in earlier papers have been found in later
samples and remain to be described, this paper is the last of our
major descriptive accounts of the morphologies of this exceptionally
important group of deep sea bivalves.

In this paper we give an account of a number of nuculanacean
species belonging to the families Neilonellidae and Nuculanidae
present in our collections from the deep Atlantic. Related species
already described are refered to only when essential for descriptive
and comparative purposes. Unlike previous papers in this series
most of the species described below are known, but only from their
shell characters. This is in part due to the fact that many species come
from upper-slope depths, and thus more likely to have been sampled

© The Natural History Museum, 1996

in the past, and in part due to the fact that they are relatively large and
thus less likely to have been lost due to the coarseness of nets used
in earlier expeditions. Many earlier descriptions of the shell are far
from adequate and new descriptions are given.

We have followed the methods and approach of earlier papers in
this series (Allen and Hannah, 1989; Allen and Sanders, 1973, 1982;
Allen, Sanders and Hannah, 1995; Rhind and Allen, 1992; Sanders
and Allen, 1973, 1977, 1985). From stereoscopic microscope ex-
amination of shell features and whole mounts of the body stained in
haemotoxylin, from dissected specimens and serial sections stained
with trichome techniques, we give detailed descriptions of the shell
and internal morphology of key species. Descriptions of related
species are limited to points of difference and importance.

Much of the material was taken by ourselves on numerous
expeditions by research vessels of the Woods Hole Oceanographic
Institution. These include the ‘Atlantis’, ‘Atlantis II’, ‘Chain’ and
‘Knorr’. Other samples were taken by JAA on the British research

102

vessels ‘Sarsia’ and ‘Discovery’. In addition to these, deep-sea
bivalves from a series of French expeditions using the research
vessels “La Perle’, “Cryos’ and ‘Jean Charcot’ were kindly donated
by our French colleagues. At present this material, other than the
types of new species and cited specimens, is housed at the Woods
Hole Oceanographic Institution and the University Marine Biologi-
cal Station Millport. On completion of our studies, it is our intention
to return the French collections to the Museum National d’ Histoire
Naturelle, Paris and our own collections to the U.S. National Mu-
seum and the Natural History Museum, London.

Museums are abbreviated as follows:- ANSP — Academy of
Natural Sciences, Philadelphia; BMNH — Natural History Mu-
seum, London; MCZ — Museum of Comparative Zoology, Harvard;
MNHN — Museum National d’Histoire Naturelle, Paris; SAM —
South Africa Museum; USNM — United States National Museum,
Washington, D.C.; ZMHU — Zoologisches Museum, Humbolt—
Universitat, Berlin, ZMUC — Zoological Museum, University of
Copenhagen.

Sampling gear is abbreviated as follows:- AD — anchor dredge; CP
— beam trawl; CV — Blake trawl; DS — epibenthic sledge Sanders
(COB); ES — epibenthic sledge (WHOI); KG — USNEL boxcorer;
OS — epibenthic sledge (SMBA); WS - epibenthic sledge (IOS).

ABBREVIATIONS TO THE TEXT-FIGURES

AA anterior adductor muscle
AN anus

AR anterior pedal retractor muscle
AS anterior sense organ

BG “‘byssal’ gland

CG cerebral ganglion

CM caecum

CV cerebro-visceral commissure
DD digestive diverticula

DH dorsal hood

DT ___ digestive ducts

FA feeding aperture

FG fused gill tissue

FR faecal rod

jul foot
GA _ gill axis
GI gill

GP gill plate

GS gastric sheild

HG hind gut

HP hinge plate

HT hinge teeth

IE internal ligament or resilium
LO opisthodetic external ligament
MG combined mid gut

MM _ mantle margin

OE oesophagus

PA posterior adductor muscle

PE sensory papilla

PG pedal ganglion

PL palp

PP palp proboscis

PR posterior pedal retractor muscle
PS posterior sorting area

SE siphonal embayment

SP combined siphon

J.A. ALLEN AND H.L. SANDERS

SR siphonal ridge
SS style sac

SvP sensory tentacle
SM stomach

VG visceral ganglion

Family Neilonellidae Schileyko 1989

Shell usually robust, inflated, moderately large, not particularly
elongate, more or less ovate, shell posteriorly extended to some
degree and may be acutely rounded or carinate, usually marked
concentric sculpture; umbo prominant, anterior to midline; hinge
teeth taxodont, continuous or interrupted below the umbo; ligament
external, sometimes with an internal component; siphons present;
hind gut either a single loop or a series of loops and coils to the left
and right of the body.

The family comprises four genera, Neilonella, Pseudotindaria,
Neilo and Protonucula (Allen and Hannah, 1986). By reason of their
external ligament, the neilonellids in the past have been included in
the family Malletiidae, however this family was shown to be an
assemblage of unrelated taxa and is now much restricted (Sanders
and Allen, 1985). The robust, ovate, concentically ridged shells of
the neilonellids are in marked contrast to the thin, translucent,
elongate shells, lacking any marked concentric sculpture, of the
malletiids.

Genus NEILONELLA Dall 1881

TYPE SPECIES. Leda (Neilonella) corpulenta Dall 1881; OD.

Shell moderately robust, relatively wide, strong concentric sculp-
ture, anterior margin rounded, posterior margin slightly attenuate
and may be acutely rounded, not carinate; umbo prominant, anterior
to the midline; hinge plate moderately strong, many chevron teeth,
small gap between anterior and posterior series; external ligament
opisthodetic, inserting in an external gutter in each valve, with
minute internal resilifer, siphonal embayment shallow; hind gut
single loop to the right of the body.

Genus PSEUDOTINDARIA Sanders and Allen 1977

TYPE SPECIES. Pseudotindaria erebus (Clarke 1959); OD.

Shell robust, relatively wide, anteriorly and posteriorly rounded,
not carinate, strong concentric sculpture; hinge plate strong with
numerous chevron teeth continuous below umbo; ligament external,
anterior part short, posterior part elongate; hind gut with complex
series of loops and coils to the right and left of the body.

Genus NEILO Adams 1854

TYPE SPECIES. Neilo cumingii Adams 1854; by monotypy.

Shell robust, relatively wide, moderately elongate and posteriorly
extended, postero-dorsal margin straight or slightly concave, cari-
nate, posteriorly truncate or slightly rostrate, postero-ventral margin
may be somewhat sinuous, two rounded radial ridges from umbo to
posterior margin, concentric sculpture; hinge plate well-developed;
numerous chevron teeth, anterior and posterior series separate and
may differ in size (anterior larger); ligament external.

DEEP-SEA PROTOBRANCHIA (BIVALVIA)
Genus PROTONUCULA Cotton 1930

TYPE SPECIES. Protonucula verconis Cotton 1930; OD.

Shell relatively fragile, oval, compressed, glossy, concentric sculp-
ture; umbo prominent; hinge plate narrow, chevron teeth squat,
broad, continuous; ligament relatively small, external, amphidetic.

Neilonella salicensis (Seguenza 1877)

TYPE SPECIMEN. Whereabouts unknown.

TYPE LOCALITY. Upper Pliocene fossil, southern Italy.

CITED SPECIMENS. BMNH 1995051.

Leda pusio var.latior Jeffreys 1876a, p.190, nom. nud.; 1876b,
p.430.

Leda pusio Jeffreys 1879, p.578, in part.

Leda pusio var.salicensis Seguenza 1877, p.1178, pl.4, fig.20.

Yoldia sericea var.striolata Verrill 1884, p.226; 1885, p.576.

Leda salicensis Locard 1898, p.348, pl.14. figs 22-25.

Neilonella subovata Verrill and Bush 1897, p.57, figs 7, 8, 22; type
locality: Georges Bank to Cape Hatteras, 125-1731 fms; syntype:
USNM 34826 (examined by HLS).

Tindaria (Neilonella) guineensis Thiele 1931, in Theile and Jaeckel
1931, p.50, pl.3, fig.70; type locality; Gulf of Guinea, 710-
2492m; type: ZMHU (not seen).

Neilonella guineensis Knudsen 1970, p.59, text-fig.39, pl.5, fig.3,
pl.6, figs 8-10.

Neilonella schepmani Prashad 1932, p.27, pl.1, figs 50, 51; type
locality; Banda Sea, Siboga sta.221, 2798m; ZMHU (not seen).

Pseudoneilonella salicensis Laghi 1986, p.191, text fig.1, pl.5, figs
1-7.

Pseudoneilonella latior Laghi 1986, p.192, text fig.1, pl.7, figs 7a-c.

Pseudoneilonella salicensis atlantica Laghi 1986 p.192, text fig.1,
pl.6, figs 1-7.

Pseudoneilonella montanaroe Laghi 1986, p.193, text fig.1, pl.9,
figs 4-8; type locality: off Portugal, Porcupine Expedition, 400m,
USNM No. 199739 (not seen).

Neilonella striolata (Brugnone) Warén 1989, p.252, figs 3a, 16a—d.

Warén (1989) gives a lengthy and detailed discussion of much of
the nomenclatoral history of this species although, the history is
even more complex than he reports. Warén (1989) synonymized N.
salicensis with an earlier described species N. striolata (Brugnone,
1876). The type of N. striolata is lost but from the original descrip-
tion and figure by Brugnone (1876) and those of Seguenza (1877)
(who synonymized it with Yoldia abyssicola Torrell) and later au-
thorities (e.g. Jeffreys, 1879; Locard, 1898) it is clear that the
posterior part of the shell of N. striolata is significantly different in
form to that of N. salicensis. Whereas the posterior shell margin of
N. salicensis is acutely rounded that of N. striolata is sub-rostrate
with the posterior limit of the shell more ventral in position and the
distal postero-dorsal margin more steeply angled (Figs 1,2 & 4).

The brief description of N. guineensis by Theile in Theile and
Jaeckel(1931) was enlarged upon by Knudsen (1970) who com-
pared specimens from the Galathea Expedition with those of the
Valdivia and Siboga Expeditions. From our examination of the
Galathea material from 02°17'S 08°10'E (2770m) and our own speci-
mens from 02°32'S 08'18'E (2514m) we conclude that N. guineensis
and N. salicensis are the same species. Knudsen (1970) also
synonymized N. schepmani with N. guineensis. Although N.
schepmani is from the Banda Sea (Prashad, 1932) which might cast
doubt on this synonymy, it must be remembered that N. salicensis is
a very widespread species and we believe that it is comparable to

103

Fig. 1. ‘Yoldia abyssicola’ Torell. Right valve, redrawn from Seguenza
(1877), synonymized with Leda producta Monterosato and Yoldia
striolata Brugnone. Scale = 1mm.

Ledella sublevis, which also has a widespread distribution in the
Atlantic and extends into the southwest Pacific (Allen and Hannah,
1989).

Further compexity in the synonymy of N. salicensis concerns so-
called varieties of “Leda pusio Philippi’ a species that has recently
been investigated by Laghi (1986).

Fig. 2. Neilonella salicensis. a, view of shell, from Atlantis II station 73
in the North America Basin, drawn from the left side; b, outline of shell
from Biogas VI station DS 86 in the West European Basin to show
difference in shape. Scale = 1mm.

L. pusio 1s rostrate and not a neillonellid, but a ledellid, possibly
synonymous withL.acuminata (Jeffreys 1870)(Laghi, 1986). Jeffreys
(1879) reporting on Leda pusio taken by the ‘Lightning’ and *Porcu-
pine’ Expeditions, refers to what he thought was a variety of this
species which he had previously named L. pusio var.latior
(Jeffreys,1876) and which he changed to L. pusio var.salicensis of
Seguenza (1877). Laghi (1986) proposed a new genus
Pseudoneilonella to accommodate this latter and raised to species
level a number of the records of Jeffreys (1876, 1879). Since then,
Warén (1989) has synonymized these with Neilonella salicensis and
this we confirm.

Jeffreys (1879) also listed a further variety which he called
semistriata and which is now regarded as a separate species (Warén,
1989). In his detailed analysis Warén (1989, figs 17E & F) also

104

figures what he describes as ‘Neilonella latior (Jeffreys)?, young
syntype of Leda sericea Jeffreys, Valorous Expedition, Stn 12,
USNM 199595’ These valves are equilateral in shape and differ in
outline from N. salicensis. We have specimens of this species in our
collections and these we intend to describe in a later paper.

Locard (1898), not mentioned by Warén (1989), came to the same
conclusion as ourselves and recognized three entities, Leda pusio,
L. striolata and L. salicensis, accurately separating them on shell
characters, the most significant of these being the more elongate,
triangular form and greater post-umbonal length of L. salicensis as
compared with L. pusio, both of which he figures.

There is a relatively wide degree of variation in the height, length
and post-umbonal length of the shell in N. salicensis and this
variation is similar in populations from different basins (Figs 4 & 5).
This may, in part, explain why this species has been described anew
so many times.

MATERIAL:
Cruise Sta Depth No _ Lat Long Date Gear
(m)
NORTH AMERICA BASIN
AtlantisIl 62 2496 13 39°26.0'N 70°33.0'W 21.8.64 ES
12 64 2886 2 38'46.0'N 70°06.0'W 21.8.64 ES
73 1330- 495 39°46.5'N 70°43.3'W 25.8.64 ES
1470
Chain50 87 1102 6 39°48.7'N 70°40.8'W 6.7.65 ES
Chain58 103 2022 217 39°43.6'N 7037.4'W 4.5.66 ES
AtlantisII 30131 2178 119 39°38.5'N 70°36.5'W 18.12.66 ES
Chain 88 210 2024- 48 39°43.0'N 70°55.5'W 23.2.69 ES
2064
GUYANA BASIN
Knorr 25 293s: 1456— 2 08'58.0'N 54°04.3'W 27.2.72 ES
1518
295 1000— 1575 08°04.2'N 54°21.3'W 28.2.72 ES
1022
297 508— 194 0745.3'N 5424.0'W 28.2.72 ES
523
299 1942- 1 0755.1.N 5542.0'W 29.2.72 ES
2076
307 3835— 2 12°34.4,N 58'59.3'W 3.3.72 ES
3862
WEST EUROPEAN BASIN
Sarsia $33 1537- 6 43°41.0'N 0336.0'W 13.7.67 ES
1830
S37 yi) 43°39.2'N 0330.2'W 15.7.67 ES
S40 860 4 43°35.6'N 0324.8'W 15.7.67 ES
S44 1739 60 43°40.8'N 03°35.2'W_ 16.7.67 ES
S50 2379 16 43°46.7'N 03°38.0'W 18.7.67 ES
S65 1922, 2 4615.0'N 04°50.0'W 25.7.67 ES
Chain 106 313 1491— 432 51°32.2'N 12°35.9'W 17.8.72 ES
1500
316 = 2173— 583 50°58.7'N 13°01.6'W 18.8.72 ES
2209
La Perle DS11 2205 1 4735.'N 0833.7'W 8.8.72 DS
Biogas I
J.Charcot DS25 2096 9 44°08.2'N 0415.0'W 1.11.72 DS
Polygas
J.Charcot DS32 2138 2 4732.2'N 0805.3'W 19.4.73 DS
Biogas II
BiogasIII DS38 2138 2 4732.2'N 0835.8'W 25.8.73 DS
DS49 1845 70 4405.9'N 0415.6'W 31.8.73 DS
BiogasIV DS52 2006 16 4406.3'N 04°22.4'W 18.2.74 DS
DS63 2126 5 4732.8'N 0835.0'W 26.2.74 DS
Cryos CP07 2170 5 44°09.8'N 04°16.4';W 21.6.74 CP
Biogas V
J.Charcot DS77 4240 1 4731.8'N 09°34.6'W 24.10.74 DS
Biogas VI DS80 4720 4 4629.5'N 1029.5'W 26.10.74 DS
DS82 4462 1 44°25.4'N 04°50.8'W_ 29.10.74 DS
DS86 1950 198 44°04.8'N 04°18.7'W 31.10.74 DS

J.A. ALLEN AND H.L. SANDERS

DS87 1913 173 4405.2'N 04°19.4';W 1.11.74 DS
DS88 1894 31 44°05.2'N 04°15.7'W__ 1.11.74 DS
Incal DSOI 2091 98 57°59.2'N 1041.3'W 15.7.76 DS

DS02 2081 91 5758.2'N_10'48.5'W__16.7.76 DS
CPO1 2068 19 S757.7'N . 1055.0 W 167-76) @P
DSO5 2503 3 5628-UN LL 17 WwW 18-7776 Ds
OSO1 2634 4 5014.4'N _13'10.9'W__ 30.7.76 OS
WS02 2498 1 50°19.3'N _12°55.8'W__30.7.76 WS
CP10 4823 2 48°25.5'N 15°10.7'W 31.7.76 CP
WS03 4829 1 48°19.2'N 15°23.3'W 1.8.76 WS
Challenger 232 2195 3 S5T17.0N 1016.0'W 19.5.83 ES
7/83
CANARY BASIN
Discovery 6701 1934 8 2745.2'N 14°13.0'W_ 16.3.68 ES
SIERRE LEONE BASIN
Atlantis] 142 1624 20 1030.0N 1751.5'W 5.2.67 ES
31 1796
147 2934 16 1038.0'N 1752.0'W 23.2.67 ES
ANGOLA BASIN
Atlantis] 191 1546— 52 23105:0/S, 1231 512s S17 5/68.8S
42 ISS)
200 2644- 7 0943.5'S 1057.01 225:68 ES
2754
201 1964— 41 09°25.0'S 11°35:0'H 423.5.68° ES
2031
202 1427- 21 08°56.0'S_ 12°15.0'E 15.5.68 ES
1643
Walda DS20 2514 4 02°32.0'S O818.1'E -——71 DS
DS25 2470 31 02°19.8'S_ 0749.2E -—-71 DS

In addition to the material listed above we have examined the
following specimens from the Porcupine and Valorous Expeditions
housed in the BMNH:-— 85.11.5.397—-402; 6.9.27,28; 85.11.5.494-5;
89.11.11.10—13; 89.9.5.26—9; 77.11.28.24. We have also examined
specimens from the Galathea Expedition housed in the ZMUC, and
specimens mostly from the U.S.Fish Commission expeditions housed
in the USNM and MCZ.

DISTRIBUTION. Common throughout the Atlantic north of the
Argentine and Cape Basins and south of the Norwegian and Arctic
Basins. It is also found in the southwestern Pacific. It mainly occurs
at slope depths, occasionally at abyssal depths (West European
Basin), from 508m to 4829m.

Fig. 3. Neilonella salicensis. a, internal inclined ventral view of the
hinge plate and teeth of a left valve; b, dorsal view of shell to show the
extent of the external ligament and detail of sculpture. Both specimens
taken from Walda station DS 25 in the Angola Basin. Scale = 1mm.

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

Fig. 4. Neilonella salicensis. A series of shells, from Atlantis II station 73
from the North Atlantic Basin, in lateral view from right side to show
change in shape with increasing size. Scale = Imm.

SHELL DESCRIPTION (Figs 2—4)
Shell robust, moderately elongate, moderately wide, ornamented

ele.
goe

=| (ar
ce
Boe

105

with concentric ridges sometimes in groups of three to four well-
defined ridges alternating with two to to three slighty less
well-defined ridges slightly wider spaced than the former, light to
dark straw-coloured periostracum; umbos moderately prominant,
somewhat anterior to mid-line (postumbonal length c.54% of total
length), inward and slightly anterior facing; dorsal shell margins
deep set close to umbo but no lunule or true escutcheon, antero-
dorsal margin slopes down to join anterior and ventral margins in
smooth curve, postero-dorsal margin almost straight, may be
slightly angled at posterior limit of hinge short of acutely rounded
posterior margin; posterior limit of shell somewhat dorsal to mid
horizontal line, anterior limit of shell at mid line; posterior margin
of smaller specimens less acutely rounded; hinge plates elongate,
moderately broad, increasing slightly in width distally, anterior
and posterior hinge teeth series meet below umbo with no edentu-
lous space between, teeth numerous, up to 19 in posterior series
and 14 in anterior series depending on size of specimen, obtuse
chevron-shape, proximal hinge teeth very small, those more distal
elongate and so closely articulated that it maybe impossible to
separate valves without damage to them; internal ligament
(resilium) microscopic, present ventral to umbo at outer margin of
hinge plate, external ligament opisthodetic, relatively short, short
anterior part present. Maximum total length of present specimens
8.0mm.

As in most deep-sea protobranchs, there is a change in the shape
of the shell outline as growth occurs (Figs 4 & 5), although this is not
as marked as in many protobranch species (e.g. Ledella spp. Allen
and Hannah, 1989). The ratio of postero-umbonal length to total
length increases and at the same time the height to total length
decreases so that larger shells (>3mm total length) are more
posteriorly attenuate than smaller specimens. There is a fair degree
of variation in the ratios which is not related to the different
populations sampled. Unusually in some samples the length fre-
quency histograms are skewed to the right (Fig. 6) and with clearly

Length (mm)

Fig. 5. Neilonella salicensis. The ratios height to total length (H/TL)(large symbols) and post-umbonal length to total length (PL/TL)(small symbols)
plotted against total length to show changes in shell proportions with increasing length. Open circles are specimens from Biogas III station DS 49 West
European Basin, closed circles from Sarsia Station S44 West European Basin and closed squares, from Chain 58 station 103 North America Basin.

106
30

20

N

syzawn

10

J.A. ALLEN AND H.L. SANDERS

LENGTH (mm)

Fig. 6. Neilonella salicensis. Length/frequency histogram of a sample taken from Atlantis II station 73 from the North America Basin.

marked size groups. It is unclear whether these latter relate to annual
settlements or to fortuitous periodic settlements.

INTERNAL MORPHOLOGY (Figs 7 & 8)

This was one of the few deep-sea species that were kept alive for a
few weeks following the processing of the sample. The external drab
olive/yellow of the shell is in marked contrast to the spectacularly
vivid array of colours of the body organs. The stomach is a bright
emerald green, the digestive gland a bright olive green and the gills
are bright red. The gill plates are particularly vivid below the frontal
cilia and dorso-laterally, in addition the mantle overlying the gills is
also red. The margins of the palps are a diffuse pink as too is a band
underlying the crest of the inner folds. The red and pink pigments are
probably a cytochrome. The blood is not red in colour and probably
contains a haemocyanin as do other protobranchs (Taylor, Daven-
port and Allen, 1995). Elsewhere the palps are pale yellow and the
yellow/pink effect is in marked contrast to the palp proboscides
which are pure white.

PL

Fig. 7. Neilonella salicensis. Semidiagrammatic view of the internal
morphology as seen from the right side. See abbreviations to text-figures
on p. 102. Scale = 1mm.

The mantle has three marginal folds of which the inner is fused at
the posterior end to form the siphon. Fusion is minimal, restricted to
the dorsal margin of the siphon (Fig. 8). Ventrally the siphonal
margins are unfused as too are the longitudinal ridges that mark the
division between the dorsal exhalent and ventral inhalent channels.
The gill axes attach to the inner ends of the longitudinal ridges.
There is a shallow siphonal embayment and attached to its inner
limit on the left or the right side is a siphonal tentacle which in living
specimens extends beyond the shell margin at distance equal to a
third of the shell length. Ventral to the anterior adductor muscle there
is an elongate anterior sense organ, which consists of a flap of tissue
derived from the middle sensory fold. A major ciliated rejection tract
is present on the inner face of the inner mantle fold. The adductor
muscles are relatively small, unequal in size, with the posterior the
smaller. The posterior muscle is round in cross-section while the
anterior is bean-shaped.

The gills, with up to 26 plates, are slung from a horizontal axis
extending from the base of the siphon to a point about half way
across the body. Individual gill plates are exceptionally elongate for
a deep-sea protobranch. The foot is broad and the divided sole has
papillate margins, the anterior papillae are the more pronounced.
There is a small median papilla present posterior to the aperture to
the ‘byssal’ gland. The latter is extremely large. The pedal muscles
consist of a pair of broad posterior retractors, one on each side of the
hindgut anterior to the posterior adductor, and a series of four pairs
of anterior retractors posterior to the anterior adductor. The two
inner muscles of the four lie more close together than to the two
outer.

The palps are relatively large with up to 27 inner ridges depending
on the size of the specimen. Each bears a long narrow palp probos-
cis. A ciliated rejection tract traverses the lateral face of the foot at
the junction of of the muscular and visceral parts and the posterior
ventral point of the palp is positioned at the posterior limit of this
tract in the living animal.

The mouth is set far posterior to the anterior adductor. The
oesophagus curves first antero-dorsally to meet the inner face of the
anterior adductor then postero-dorsally to open on the anterior face
of the stomach. The stomach is large and slung diagonally within the
visceral mass. The pedal muscles form a ventral ‘basket’ in which
the stomach rests. The stomach, which is similar to that of other

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

FA

Fig. 8. Neilonella salicensis. Detail of internal morphology; a, lateral
view from the right side of the stomach and style sac; b, internal view of
a dissected gastric shield; c, diagrammatic enlargement of the siphonal
region to show the relationship of the parts. See abbreviations to the
text-figures p. 102. Scales = 0.5mm (A); 0.1mm (B).

protobranchs (Purchon, 1956), is one third lined with a gastric shield
dorsally and to the left (Fig.8). The unlined right wall bears very few
sorting ridges. The style sac is flask-shaped rather than the more
usual conical outline of other protobranchs. The combined mid gut
is guarded by minor and major typhlosoles. The hind gut penetrates
the foot to a point ventral to the pedal ganglia before taking a course
posterior to the stomach and thence to form a loop to the right side
of the body. This single loop extends anteriorly as far as the anterior
adductor muscle and where it then takes a dorsal course along the
margin of the body to the anus. The hind gut has a particularly wide
diameter compared with most other deep-sea protobranchs and has
a well-marked typhlosole present along its entire length. The diges-
tive gland which lies anterior and dorso-lateral to the stomach has
three sections each connecting with the stomach via a duct. The
apertures of the ducts are ventral, and left latero-ventral to the
oesophageal aperture.

The nervous system is of a typical protobranch design with
elongate pairs of cerebral and visceral ganglia and large ovoid pedal
ganglia. These are connected by very stout cerebro-visceral and
cerebro-pedal commissures. A statocyst lies dorsal each pedal gan-

107

glion. From visceral ganglia three main nerves pass to the gill, hind
gut and mantle/siphon, and from the cerebral ganglia nerves pass to
the palps and mantle.

The sexes are separate, specimens greater than 4mm total length
have gonads. The gonad first develops at the periphery of the visceral
mass and as it matures it spreads across the lateral surface of the
viscera. On the right side of the body, apart from a small portion
postero-dorsal to the loop of the hind gut the gonad does not extend
beyond the confines of the of the loop. While different samples show
different degrees of maturity, the specimens of each sample appear
to be maturing synchronously. The ratio of males to females is
approximately 50:50.

Neilonella hampsoni new species

TYPE SPECIMEN.
1995050.

Holotype BMNH 1995049; paratype BMNH

TYPE LOCALITY. Atlantis II cruise 31, station 155, Sierra Leone
Basin, 00°03.0'S 27'48.0'W, 3730-3783m.

MATERIAL:

Cruise Sta. Depth No Lat Long Date Gear
(m)

SIERRA LEONE BASIN

Atlantis 11 155 3730-3 00°03.0'S 27°48.0'W 14.2.67 ES

ii 3783

J.Charcot DS035150 1 10'59.0'N 45°15.0'W 16.11.77 DS

Vema

DISTRIBUTION. Anabyssal species, to date only found in the Sierra
Leone Basin at depths from 3730m to 5150m.

SHELL DESCRIPTION (Figs 9 & 10)

Shell robust, oval, wide, ornamented with concentric ridges, straw-
coloured periostracum; umbo prominant, anterior to midline
(postumbonal length c.60% of total length in large specimens),
inward facing; lunule and escutcheon, both well-defined; postero-
dorsal margin in lateral view almost straight, slopes relatively
steeply from umbo to proximal limit of hinge, rounded angle to
posterior margin, anterior and ventral margins form a smooth curve,
distally antero-dorsal margin slightly concave then slopes steeply in
smooth curve to anterior margin; anterior limit of shell coincides

Fig. 9. Neilonella hampsoni. Lateral view of the right valve of the
holotype, from Atlantis II station 155 from the Sierra Leone Basin.
Scale = 1mm.

108

Fig. 10. Neilonella hampsoni. a, lateral view of the hinge plate of the
right valve of a paratype; b, dorsal view of the shell of the holotype.
Both specimens taken from Atlantis II station 155 from the Sierra Leone
Basin. Scales = 1mm.

with horizontal midline, posterior limit of shell immediately ventral
to mid line; hinge plate stout extending along most of the dorsal shell
margin, anterior and posterior tooth series meet below umbo, with
faint suggestion of an edentulous space between, 13 posterior and 10
anterior teeth in specimen 3.9mm total length, teeth increase in size
distally, teeth chevron-shaped, obtuse, so much so that teeth appear
to be a straight line transverse to hinge plate; ligament opisthodetic,
external, short, anterior outer layer extremely short, hidden beneath
umbo, no resilium.

Maximum total length of present specimens is 7.5mm.

Apart from N. salicensis, from which it differs in having a shorter,
wider shape, and well-marked lunule and escutcheon, the only other
protobranch species with which it has some similarity is ‘Leda’
sericea var ovata Jeffreys 1876 (Jeffreys, 1879). One of us (JAA) has
examined specimens of this latter species in the Natural History
Museum, London, (BMNH 85 11 5483-84) and find that L. sericea
is more ovate, with the dorsal margins much less sloping, a more
anteriorly positioned umbo and a much more narrow hinge plate.

INTERNAL MORPHOLOGY

The morphology is similar to Neilonella salicensis. Such differences
that do exist include the adductor muscles, both of which are small,
similar in size, but with the posterior oval and the anterior round in
cross section. The foot is somewhat smaller but with a moderately
large byssal gland with a small, hooked, median papilla posterior to
its aperture. Except for the posterior quarter of their length, the
margins of the divided foot are finely papillate. There are approxi-
mately 20 gill plates and 25 ridges on the palps of a specimen 3.9mm
total length. The hind gut makes a simple loop to the right side of the
body, it has a wide lumen (0.21mm in diameter) with a single well-
defined typhlosole running its entire length. The stomach is large
and the mouth lies some distance posterior to the inner wall of the
anterior adductor. The kidney extends in a narrow band from the
posterior margin of the posterior adductor, anteriorly narrowing over
the viscera, and terminating at the posterior edge of the digestive
diverticula.

J.A. ALLEN AND H.L. SANDERS

It is named after our good friend and colleague George Hampson
who accompanied us on so many of our cruises and without whom
sampling at abyssal depths would not have been the resounding
success that it proved to be.

Neilonella corpulenta (Dall 1881)

TYPE LOCALITY. Blake station off Havana, 823m (station number
not recorded but, only station 51, 23°11.0'N 82°21.0'W, is listed as
having a depth of 450fm (823m) (Smith, 1888)).

TYPE SPECIMEN. Holotype, U.S. National Museum 63169. Cited
specimen: BMNH 1995048.

Leda (Neilonella) corpulenta Dall, 1881, 125; 1886, 254, pl. 7, figs.
la, 1b.
Neilonella (N.) corpulenta Laghi 1986, pl.9, figs 1-3.

MATERIAL:

Cruise Sta. Depth No Lat Long Date Gear
(m)

BRAZIL BASIN

Atlantis] 162 1493 1 08°02.2'S 3403.0'W 19.2.67 ES

31

The type specimen has been examined by us.

DISTRIBUTION. An upper slope species previously recorded only
from the Gulf of Mexico but here found in the Brazil Basin. It occurs
at depths from 347m to 1493m.

SHELL DESCRIPTION (Fig. 11)

Dall (1881) gave an adequate description which was later (Dall,
1886) augmented by good internal and external lateral views of the
shell. The specimen collected from the Brazil basin differs little
from the type (Dall, 1881, 1886)(Fig. 11):-

Shell elongate, solid, oval, ornamentated with concentric ridges;
umbo not particularly large or elevated, somewhat anterior to the
mid line; postero-dorsal margin almost straight, slightly upturned
posterior to the distal limit of the hinge, then sharply and smoothly
curved to posterior margin, ventral margin shallow smooth curve,
not posteriorly sinuous, anterior margin smoothly curved, antero-
dorsal margin relatively steeply angled, distally slightly raised;
hinge plate elongate, relatively wide, hinge teeth chevron-shaped, 9
in anterior and 12 in posterior series; external ligament slightly
opisthodetic, short; resilium small ventral to umbo.

Dall (1881) states that there are an equal number of teeth in the
anterior and posterior series (15), however the type specimen which
is larger than the present specimen, has 17 anterior and 20 posterior
teeth.

The total length of present specimen is 3.1mm.

INTERNAL MORPHOLOGY

Both adductor muscles are oval in cross section, the anterior is
somewhat larger than the posterior but neither is particulaly large.
The foot is relatively short with large marginal papillae. The palps
are relatively short with 7 broad internal ridges. The gill is also short.
The siphonal embayment is shallow and the siphons similar to those
described for N. salicensis. The hind gut forms a single loop to the
right side of the body and has a typhlosole along its entire length.

Neilonella whoii new species

TYPE SPECIMEN.
1995053.

Holotype BMNH 1995052; paratypes BMNH

DEEP-SEA PROTOBRANCHIA (BIVALVIA) 109

Fig. 11. Neilonella corpulenta. a, an external lateral view of the right valve of specimen No 63169 from the USNM and an internal lateral view of the
central region of the hinge of the same valve; b, lateral view of the intact shell, from Atlantis II station 162 from the Brazil Basin, and an internal view of
the left valve of the same specimen to show detail of the hinge plate. Scales = 1mm.

CITED SPECIMEN. BMNH 1995054. BiogasIV DS53 4425 30 44304'N 04°56.3'W 19.2.74 DS
TYPE LOCALITY. | Chain cruise 50, station 78, North America Ba- an ati s ita oe oe a
sin, 38:00.8'N 69°18.7'W, 3828m. DS60 3742 2 47268'N 09°07.2'W 24.2.74 DS
Cryos DS66 3480 4 47°28.2'N 09°00.0'W 17.6.74 DS
MATERIAL: Biogas V
: J.Charcot DS75 3250 4 47°28.1'N 09°07.8'W 22.10.74 DS
eee Mee NOwe Dat Long ‘Date Gear Biogas VI. DS76 4228 8 © 4734.8'N 09°33.3'W 23.10.74 DS
a a a a CP14 4237 1 4732.0'N 09°35.9'W 23.10.74 CP
WEST EUROPEAN BASIN DS78 4706 29 4631.2'N 1023.8'W 25.10.74 DS
hain 106 323 3356-7 ° SO0083'N 13°53.7W 21.8:72 ES DS79 4715 10 4630.4'N 10°27.1'W 26.10.74 DS
3338 CP18 4721 1 4630.5'N 10726.0'W 26.10.74 CP
326 3859 5 50°04.9.N 14°23.8'W 22.8.72 ES DS81 4715 1 4628.3'N 1024.6'W 27.10.74 DS
328 4426- 6 5004.7'N 1544.8'W 23.8.72 ES CP19 4434 3 44°24.9'N 04°51.3'W 28.10.74 CP
4435 DS82 4462 16 44°25.4'N 04°52.8'W 29.10.74 DS
330 4632 16 5043.5'N 17°51.7'W 24.8.72 ES J.Charcot OSO1 2634 3 SOS: 2N IGO'W S30776 OS
J.Charcot DS204226 2 4733.0'N 09°36.7';W 24.10.72 DS Incal DS11 4823 1 48186'N 15°12.0'W 1.8.76 DS
Polygas DS224144 2 47°34.1'N 09°38.4';W 25.10.72 DS CELI S 23 OL 1e2N oy W/ 8 One Cr
DS23 4734 18 4632.8'N 10721.0'W 26.10.72 DS OS02 4829 6 48°19.1'N 15°15.5'W 2.8.76 OS
DS28 4413 1 44°23.8'N 04°47.5'W 2.11.72 DS OS05 4296 3 4732.9N 09°34.7'W 7.8.76 OS
J.Charcot CV232034 1 4732.7'N 08°34.2'W 25.8.73 CV OS06 4316 3 4727.9'N 09°36.0'W 9.8.76 OS
Biogas III DS41 3548 4 47283'N 09°04.2'W 268.73 DS DS16 4268 1 4730.3'N 09°33.4'W 9.8.76 DS
CV27 4023 1 4734.2'N 09°32.4;W 28.8.73 CV WS094277 2 4727.9'N 09°34.0'W10.8.76 WS
CV304518 53 4632.8'N 10°20.0'W 28.8.73 CV
DS47 4230 2 44°26.8'N 04°50.7'W _31.8.73. DS CANARY BASIN
J.Charecot CV344406 1 4427.2'N 04°49.1'W 19.2.74 CV Discovery 6711 2988 1 2714.9'N 15°36.3'W 19.3.68 ES

110

SIERRA LEONE BASIN
Atlantis II 146 2842- 2 1039.5'N 1744.5'W 6.2.67 ES
31 2891
147 2934 4 1038.0'N 1752.0'W 6.2.67 ES
148 3814 4 1037.0'N 1814.0'W _ 7.2.67 ES
3828
149 3861 1 1030.0N 1818.0'W 7.2.67 ES
GUINEA BASIN
J. Charcot DS28 1261 2 04°21.2'N 04°35.2'E _ 7.8.71 DS
Walda
ANGOLA BASIN
Atlantis II 195 3797 46 1449.0'S 09°56.0'E 19.5.68 ES
42 197 4595 25 1029.0'S 0904.0'E 21.5.68 ES
198 4559- 20 1024.0'S O09°09.0'1E 21.5.68 ES
4566
199 3764— 3 09°49.0'S 1033.0E 22.5.68 ES
3779
200 2644 8 09°43.5'S 1057.0E 22.5.68 ES
2754
NORTH AMERICA BASIN
Atlantis Il 2 Vise, 22 38°05.0'N 69°36.0.W 22.5.61 AD
264
AtlantisII 64 2886 2 38°46.0.N 7006.0°.W 21.8.64 ES
12 72 2864 9 38 16.0N 7147.0';W 24.8.64 ES
Chain 50 76 2862 3 39°38.3'N 6757.8'W 29.6.65 ES
Wil 3806 752 3800.7'N 69°16.0'W 30.6.65 ES
78 3828 199 3800.8'N 6918.7;W 30.6.65 ES
80 4970 1 34°49.8'N 6634.0'W 2.7.65 ES
85 3834 115037°59.2'N 69°26.2'W 5.7.65 ES
Atlantis II 124 4862 1 3726.0'N 6359.5'W 22.8.66 ES
24 126 3806 48 39°37.0'N 6647.0'W 24.8.66 ES
Atlantis II 175 4667- 1 3636.0'N 6829.0'W 28.11.67 ES
40 4693
Chain 106 334 4400 3 40°'42.6'N 4613.8'W 30.8.72 ES
335 3882-5 4025.3'N 4630.0'W 31.8.72 ES
3919
Knorr 35 340 3264-95 38144'N 7020.3'W 24.11.73 ES
3356
BRAZIL BASIN
Atlantis II 156 3459 6 00°46.0'S 29°28.0'W 14.2.67 ES
31
GUYANA BASIN
Knorr 25 287 4980-72 1316.0'N 54°52.2'W 24.22.72 ES
4934
288 4417-19 1102.2'.N 55°05.5'W 25.2.72 ES
4429
291 3859- 43 1006.1'N 5514.0'W 26.2.72 ES
3868
301 2487-23 0812.4'N 55°50.2;W 29.2.72 ES
2500
303 2842- 8 0828.8'N 5604.5';W 1.3.72 ES
2853
307 3862-15 12344'N 5859.3'W 3.3.72 ES
3835
J.Charcot DS05 5100 3 10°46.0'N 42°40.3'W 19.11.77 DS
Biovema
ARGENTINE BASIN
AtlantisII 242 4382- 1 3816.9'S 5156.1'W 13.3.71 ES
60 4402
243 3815- 3 B1/S 0181S) DOS OW 4235/1
3822
247 5208— 6 AZBB:0/Su we 48 Solan Soil ES
5223
256 3906—- 8 3740.9'S 5219.3'W 243.71 ES
3917
7) SRS = iil SAS SPASM Beil JS
3317

DISTRIBUTION. An abyssal species, found widely within temper-
ate and tropical latitudes at depths ranging from 2487m to 5223m.

J.A. ALLEN AND H.L. SANDERS

SHELL DESCRIPTION (Figs 12 & 13)

Shell robust, ovate, moderately wide, ornamentated with marked
concentric ridges, straw-coloured periostracum; umbos prominant,
inwardly facing, clearly anterior of vertical midline in specimens
>3.0mm, more central in smaller specimens (post-umbonal length
c. 57% of total length); no clearly marked lunule or escutcheon,
but some specimens with faint indications; postero-dorsal margin
slight concave curve, very slightly angulate opposite limit of
hinge plate then steepening to posterior margin, posterior margin
may be somewhat flattened particularly in small specimens, ven-
tral margin moderately curved joining anterior and antero-dorsal
margins in a smooth curve, anterior and posterior limits of shell
dorsal to mid-horizontal line; hinge plate broad, continuous, elon-
gate, short chevron-shaped hinge teeth, up to 14 in posterior
series, 12 in anterior series, numbers varying with size of speci-
men, edentulous space below umbo very small; external ligament
short, opisthodetic, resilium microscopic, close to shell margin,
ventral to umbo. Maximum total length of present specimens is
9.8mm.

Neilonella whoii most closely resembles N. salicensis. It can be
separated from the latter species by its more rounded shape and
greater height. The posterior shell margin is not as acute and the
posterior limit of the shell is more dorsal in position as compared
with N. salicensis. Furthermore, the post-umbonal length of N.
whoii is somewhat longer than in N. salicensis and the hinge plate
is not so broad having a smaller ratio of anterior to posterior
teeth.

We name this species in honour of the Woods Hole
Ocenanographic Institution, through whose auspices these studies
were carried out.

INTERNAL MORPHOLOGY (Figs 14 & 15)

For the most part the morphology of N. whoii is similar to that of
N.salicensis. Of the mantle structures, the construction of the siphon
is similar, although the siphonal embayment is less deep than in N.
salincensis. The posterior adductor muscle is oval in cross-section
and not much smaller than the anterior, probably reflecting the more
rounded shell outline of N. whoii. The anterior sense organ is poorly
developed, the least developed of all the deep-sea nuculanids that
have been described to date. The gills and palps of N. whoii are
similar in size and form to those in N. salicensis with up to a
maximum of 18 gill plates and 17 palp ridges.

The foot is large with a few moderately deep papillae at the
margin. The mouth lies some distance posterior to the anterior
adductor. The stomach is large with 9 or 10 ridges forming the
porterior sorting area. The hind gut makes a single loop to the right
side of the body, the loop being somewhat larger and more smoothly
curved than that in N. salicensis. The ganglia and commissures are
not so stout as they are in the latter species.

Clearly Neilonella whoii is closely related to N. salicensis.
Although similar in form, they have markedly different depth
distributions, N. salicensis occurring mainly at lower slope
depths and N. whoii occurring mainly at abyssal depths. We believe
that in the past there may have been misidentifications, and speci-
mens of N. salicensis recorded from abyssal depths deserve
re-examination.

Specimens which are narrower and relatively smaller in height to
length ratio than those described above (Fig.16) are present in some
samples and do not occur other than with typical specimens of N.
whoii. In other respects they are no different in their morphology to
N. whoii. We consider them to be varients at the limit of a range of
shell outlines and not a subspecies.

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

eo qeutel

|

Fig. 12. Neilonella whoii. Details of shell form of specimens, from Chain station 78 from the North America Basin, the type locality; a, left lateral, b,

dorsal and ¢, anterior views intact shells; d, the hinge plate of a specimen, from Incal station DSO05 from the West European Basin; e, detail of the
umbonal region of the hinge plate of a specimen, from Chain station 78. Scales = 1mm.

Fig. 13. Neilonella whoii. Four shells in outline, from Atlantis II station
72 from the North America Basin, in left lateral view to illustrate the
small changes in shape with increasing size. Scale = 1mm.

Fig. 14. Neilonella whoii. A semidiagrammatic view of the internal
morphology as seen from the right side. For the identification of the
parts see text-figure 7, p. 106. Scale = 1mm.

111

112

Fig. 15. Neilonella whoii. The dissected stomach and style sac as seen
from a, in left lateral and b, frontal view. See abbreviations to text
figures on p. 102. Scale = 1mm.

Fig. 16. Neilonella whoii. a, right lateral view of shell of elongate form,
from Atlantis II station 242 from the Argentine Basin, in right lateral
view and b, detail of the umbonal region of the same shell in dorsal
view. Scales = 1 mm.

J.A. ALLEN AND H.L. SANDERS
Family Nuculanidae Adams and Adams 1858

A recent definition of the family is given by Allen, Sanders and
Hannah (1995).

Subfamily Ledellinae Allen and Sanders 1982

The subfamily is defined by Allen and Hannah (1989) and comprises
two genera, Ledella and Tindariopsis.

Genus LEDELLA Verrill and Bush 1897

TYPE SPECIES. Ledella bushae Warén 1978. SD — Warén 1981.

Shell small, short, robust, surface matt, concentric sculpture, in
some species scattered incomplete radial striae, usually rostrate,
single postero-dorsal ridge in some species, postero-ventral margin
very slightly sinuous, ventral margin in older specimens maybe
flattened, anterior and posterior hinge teeth series separated by
edentulous space bearing short internal amphidetic ligament
(resilium) which may be restricted to dorsal portion of hinge plate,
outer layer of ligament visible externally and maybe extended
anteriorly and posteriorly for a short distance, hind gut with various
configurations.

Genus TINDARIOPSITS Verrill and Bush 1897

TYPE SPECIES. Malletia (Tindaria) agatheda Dall 1889. OD.

Shell veneriform, matt surface, concentric sculpture, umbo large,
short rostrum defined by slight radial ridge and furrow, postero-
ventral margin slightly sinuous, anterior and posterior hinge teeth
separated by very small edentulous space, internal ligament small,
close to shell margin, external ligament robust, amphidetic.

Ledella acinula (Dall 1890)

TYPE SPECIMEN. Holotype USNM 95438.

TYPE LOCALITY. U.S. Fish Commission Steamer ‘Albatross’ Sta.
2754, 11°40'N 58°33'W, East of Tobago, 1609m.

CITED SPECIMENS. BMNH 1995047

Malletia (Tindaria) acinula Dall, 1890, 253, pl.XIIl, fig.4.
Tindaria acinula Verrill and Bush 1898, 881.
‘Tindaria’ acinula Sanders and Allen 1977, 55, figs 44, 45.

MATERIAL:
Cruise Sta. Depth No _ Lat Long Date Gear
(m)
BRAZIL BASIN
AtlantisI1I 167 943- 1 0758.0'S 3428.0'W 20.2.67 ES
31 1007
GUYANA BASIN
Knorr25 293 1456— 2 08°58.0'N 5404.3'W 27.2.72 ES
1518
295 1000—- 4 O8'01.9'N 5416.4'W 28.2.72 ES
1022
299 1942- 108 07°55.1'N 55°42.0'W 29.2.72 ES
2076
WEST EUROPEAN BASIN
Chain 106 330 4632 3 50°43.5'N 17°51.7'W 24.8.72 ES
J.Charcot DS79 3226 15 4630.4'N 1027.1'W 26.10.74DS
Biogas VI
GUINEA BASIN
J. Charcot DS28 1261 4 04°21.2'N 0435.E -—71 DS
Walda

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

The type specimen has been examined by us.

DISTRIBUTION. Found predominantly in tropical and subtropical
latitudes, and southern temperate latitudes in the eastern Atlantic, at
mid-slope to abyssal depths ranging from 943m to 4632m.

Many protobranch species with robust shells having subrostrate
or ovate outlines and with concentric ridges and external liga-
ments, in the past have been referred to the genera Malletia,
Neilonella orTindaria (e.g. Dall, 1890). Ledella acinula is a case
in point. Having addressed this problem in earlier papers (Sand-
ers and Allen, 1977, 1985), and the present, we have been able to
define more rigorously the families Tindariidae, Neilonellidae
and Malletiidae.

Dall (1890) who described large specimens of L. acinula referred
them to the subgenus Tindaria. Large specimens do show some
resemblance to neilonellids and tindariids, but had Dall seen the
shells of smaller specimens (Fig. 18), he would have been unlikely to
have made the error.

In our studies on Tindaria (Sanders and Allen, 1977) we re-
examined and briefly redescribed L. acinula, and recognized that
there was a problem in identification but deferred final judgment
until we had made further comparative studies. Now that the
Ledellinae have been reported upon (Allen and Hannah, 1989), the
taxonomic relationship of this species is clear.

That L. acinula is siphonate clearly distinguishes it from members
of the family Tindariidae. Although similar to the neilonellids in
having an external amphidetic ligament, it differs in having a small
but well-defined internal ligament and in being semi-rostrate with a
slightly sinuous postero-ventral margin. A further significant differ-
ence is the form of the hind gut and the course that it takes within the
body (Sanders and Allen, 1977). In L. acinula the hind gut is not
particularly wide in diameter and is not restricted to the right side of
the body (see below) having a configuration only known to occur in
species of the subfamily Ledellinae e.g.Ledella galatheae Knudsen

113

1970, L. oxira (Dall 1927), L. acuminata (Jeffreys 1870)(Allen and
Hannah, 1989).

SHELL DESCRIPTION (Figs 17 & 18)

Shell robust, posteriorly angulate, ornamented with concentric ridges
particularly well-defined on ventral part of shell, straw-coloured
periostracum; umbos relatively low in profile, inward facing, anterior
to midline; posterior rostral region characteristically broad and blunt
when seen in dorsal view; postero-dorsal shell margin almost straight,
angulate at posterior limit of hinge plate - particularly so in smaller
specimens, barely so in larger, posterior margin sharply rounded,
ventral margin deeply curved, postero-ventral margin slightly sinu-
ous, particularly in smaller specimens, antero-dorsal, anterior and
antero-ventral margins form a smooth curve; posterior and anterior
limits of shell at or slightly ventral to mid horizontal axis, ventral limit
of shell posterior to vertical axis through umbo; hinge plate elongate,
broad, anterior and posterior tooth series separated by relatively long
edentulous space, chevron-shaped teeth acutely angled, up to 10
anterior and 12 posterior teeth depending on size of specimen;
ligament amphidetic, external parts short, internal resilium small,
rounded, occupying upper central part of hinge plate below umbo.The
maximum total length of the present specimens is 6.0mm.

The shape of the shell changes significantly with growth (Figs 18
& 19). While the ratio of height to length remains more or less the
same, the postero-umbonal length increases from 50% to 60% of the
total length of the shell. With increasing size the postero-dorsal
margin also becomes less angulate at the posterior limit of the hinge,
also the postero-ventral margin becomes less sinuous, at most being
somewhat flattened.

INTERNAL MORPHOLOGY
This has been described and illustrated by us in our earlier studies on
the family Tindariidae (Sanders and Allen, 1977). Only essential
features relating to the taxonomy need be mentioned.

Combined siphons are present and there is a well-developed

Fig. 17. Ledella acinula. a & b, internal and external views of a left valve, from the type locality Albatross station 2754, USNM 95438; c, internal view
of left valve of specimen, from Atlantis II station 167 from the Brazil Basin; d & e, lateral view of left side and dorsal view of a shell, from Knorr station
299 from the Guyana Basin. Scale = 1mm.

114

J.A. ALLEN AND H.L. SANDERS

Fig. 18. Ledella acinula. Four shells in outline, from Knorr station 299 from the Guyana Basin, in right lateral view to illustrate changes in shape with

increasing size. Scale = 1mm.

feeding aperture ventral to the siphonal embayment. The adductor
muscles are relatively large, the anterior ovate and the posterior
more circular in cross section. The anterior sense organ lies far
anterior, ventral to the anterior adductor. The palps and gills are
moderate in size with relatively few ridges (up to 15) and plates (up
to 17) respectively. The foot has a well-defined neck, this is probably
related to the relatively large height of the shell. There is a large
‘byssal’ gland present in the heel of the foot. The hind gut first makes
a single loop on the right side of the body before passing to the left
side of the body between the oesophagus and the inner face of the
anterior adductor muscle. On the left side of the body the hind gut
forms a double coil. Because of the anterior penetration of the gut to
the left side, the mouth is displaced some distance posterior to the
anterior adductor muscle.

80 Cue : ss
H oO o-- 208% = oma a -~*~=~CS~—S

h ° ° Ae -

70

2 ee z e

e

PL, on°°

L wr e

50 e

1 2 3 4 5

Length (mm)

Fig. 19. Ledella acinula. The ratios of height to total length (H/L)(open
circles) and post-umbonal length to total length (PL/L)(closed circles)
plotted against total length to show changes in shell proportions with

increasing length. Specimens from Knorr station 299 from the Guyana
Basin.

Ledella aberrata (new species)

TYPE SPECIMEN.
1995046.

Holotype BMNH 1995045; paratypes BMNH

TYPE LOCALITY. Chain cruise 60, station 247, Argentine Basin,
43°33.0'S 48°58. 1'W, 5208-5223m

MATERIAL:
Cruise Sta Depth No _ Lat Long Date Gear
(m)
ARGENTINE BASIN
Atlantis 1] 242 4382- 2 38:16:9'S, 5156. We “ISS SES
60 4402
247 5208- 34 43°33.0'S _48°58.1'W17.3.71 ES
5223
252) 4435 4 + 3829.8'S S2i09NMWi 22371, {ES
GUYANA BASIN
J.Charcot KG135100 1 10°47.6'N 42°40.4'W 20.11.77 KG
Biovema
NORTH AMERICA BASIN
Chain 50 85 3834 1 3759.2'N 69°26.2'W 5.7.65 ES
WEST EUROPEAN BASIN
Chain 106 330 4632 3 50°43.4'N 17°51.7'W 24.8.72 ES
J.Charcot DS23 4734 5 4632.8'N 1021.0'W 1.11.72 DS
Polygas
Biogas II DS32 2138 1 4732.2'N 08'05.3';W_17.4.73. DS
BiogasITV DS54 4659 7 4631.1'N 1029.2;W 21.2.74 DS
Cryos DS68 4550 2 4626.7'N 1023.9'W 19.6.74 DS
Biogas V
J.Charcot DS78 4706 18 4631.2'N 1023.8'W 25.10.74 DS
Biogas VI DS79 4715 17 4630.4'N 1027.1'W 26.10.74 DS
DS80 4720 3 4629.5'N 1029.5'W 27.10.74 DS
DS81 4715 2 4628.3'N 1024.6'W 27.10.74 DS
INCAL CP10 4823 1 48°25.5'N 1510.7W 31.7.76 CP
DS11 4823 2 4818.8'N 1511.5'W 1.8.76 DS
WS034829 18 4819.2'‘N 15723.3'W 1.8.76 WS
CP11 4823 1 48°20.4'N 1514.6';W 1.8.76 CE
OS02 4829 1 48°19.2'N 15°15.9'W 2.8.76 OS
WS104354 1 4727.3'N 09°39.9'W 11.8.76 WS
CAPE BASIN
J.Charcot DS05 4560 2 3320.5'S 02349'E 30.12:78 DS
Walvis

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

115

Fig. 20. Ledella aberrata. a, dorsal view of shell; b, dorsal, ventral and anterior view of thickened shell; ¢, lateral view of the hinge plate of a left valve, all
from Atlantis II station 247 from the Argentine Basin; d, lateral view of the hinge plate of a right valve, from Chain station 85. Scales = 1mm.

DISTRIBUTION. In temperate and tropical basins of the Atlantic at
abyssal depths >4000m, rare in the North America Basin. Depth
range, 2138-5223m.

SHELL DESCRIPTION (Figs 20 & 21)

Shell small, ovate, relatively high, moderately wide, ornamented
with concentric ridges; umbo moderate in size, inwardly turned,
anterior to mid-line but less so in juveniles; no lunule or escutcheon;
periostracum pale straw colour; postero-dorsal margin slightly con-
vex becoming more straight with increasing size, slightly angulate at
posterior limit of hinge plate and at posterior margin, postero-ventral
margin very slightly sinuous, otherwise ventral margin deeply curved
with ventral limit posterior to vertical axis through umbo, anterior
margin sharply curved, antero-dorsal margin slightly convex with
slight change in slope at anterior limit to hinge plate; shell outline
characteristically asymmetrical, shell margin in larger specimens
changes direction of growth producing a broad flattened ventral
margin; hinge plate broad, up to 6 chevron teeth in anterior series and
7 in posterior series, edentulous space between series relatively
broad; ligament small, amphidetic, internal part restricted to upper
part of hinge plate, external part extremely short situated below
umbo. The maximum length of the present specimens is 2.6mm.

INTERNAL MORPHOLOGY (Figs 22 & 23)

The adductor muscles are moderately large and oval in shape. The
combined siphon is relatively short The dorsal margins of the
exhalent part are fused proximally for a short distance and the
ventral margins of the inhalent part are not fused but are slightly
thickened and probably adhere in living specimens. Internally where
inhalent and exhalent parts join, there is a thickened median ridge on
each side which together together with the posterior continuation of
the gill axes probably act as guides when the faecal pellets are
extruded. The siphonal embayment is small and there is a small,
slender, tentacle attached to the left side at the inner limit of the
embayment. The anterior sense organ is small and is situated ventral
to the anterior adductor muscle.

The palps are small with up to 11 broad ridges. The gills are
also small each with up to 11 plates the most posterior of which
lies some distance from the siphon. The gills are attached to the
posterior limits of the median guides by slender extensions of the
gill axis.

The hind gut is greatly extended and takes a similar but more
complex course to that described for L. acinula. Like the latter, the
hind gut passes from the right side of the body to the left immedi-
ately posterior to the anterior adductor muscle and returns by the

116

Fig. 21. Ledella aberrata. Five shells in outline to show variation in
shape with growth. a, is a specimen with a thickened margin; b, has a
slightly thickened margin; the remaining three shells are unthickened.
Scale = 1mm.

same route. Unlike the latter species, it makes a single coil on the
right side as well as a double twinned coil on the left.

The foot is unusual in having a large heel and a narrow muscular
anterior part. The marginal papillae are few in number and restricted
to the anterior margins of the sole. The sole is less deeply divided as
compared with other protobranchs. There is a large “byssal’ gland in
the heel of the foot.

Although the shell outline of the smaller specimens is more
characteristic of the genus Ledella than in larger mature specimens,
the general shell outline of L aberrata (and L. acinula) is much
deeper and more ovate than in other described species (Figs 18 & 21)
nor is it markedly rostrate. Despite this, the characters place them in
the Ledellinae (Allen and Hannah, 1989) and we see no reason for
erecting another genus.

Apart from L. aberrata, only two species of protobranchs, have
been reported as exhibiting a change in shell growth to produce a
flattened shell margin (Fig. 20). Both are ledellids, namely L. ultima
(Smith 1885) and L. solidula (Smith 1885) (Allen and Hannah,
1989). Like L. aberrata these two latter species also have elongate
hind guts. The hind gut of L. solidula is very similar to that of L.
aberrata in having double twinned coils to the left side of the body
(Fig.22), although it does not have an additional single coil to the
right as does the present species. The type of course taken by the
hind gut in L. acinula is also found in other species of Ledella (e.g.
L. oxira) (Allen and Hannah, 1989).

We named this species after the familiar appelation to which it
was referred during our original analysis of the samples.

Tindariopsis agatheda (Dall 1889)

TYPE SPECIMEN. USNM 95437, lectotype here designated.

TYPELOCALITY. U.S.Fish Commission Sta. 2754, east of Tobago,
11°40'N 58°33W, 1609m.

J.A. ALLEN AND H.L. SANDERS

Fig. 22. Ledella aberrata. Internal morphology as seen in a, right lateral
view, b, left lateral view and c¢, left ventro-lateral view. For identification
of the parts see text-figure 7, p. 106. Scales = 1mm.

CITED SPECIMEN. BMNH 1995062.

Malletia (Tindaria) agatheda Dall 1890, 252, pl. xi, fig. 10.
Tindaria (Tindariopsis) agatheda Verrill and Bush 1897, 59.
Saturnia (Tindariopsis) agatheda McAlester 1969, N235.
Tindariopsis agatheda James 1972, 98, figs 60-62.

Neilonella (Tindariopsis) agatheda Laghi 1986, 190, pl.8, figs 2-6.

MATERIAL:
Cruise Sta. Depth No _ Lat Long Date Gear
(m)
BRAZIL BASIN
Atlantis] 167 943- 1 0758.0'S 3428.0'W 20.2.67 ES
31 1007
GUYANA BASIN
Knorr 25 293 1456- 14 08°53.1'N 5404.3'W 27.2.72 ES
1518
299 1942-8 O755.1'N 5542.0'W 29.2.72 ES
2067
301 2487-7 08124'N 55°50.2'W 1.3.72 ES
2500

The type specimen has been examined by us.

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

MM

uo

Fig. 23. Ledella aberrata. Siphonal region, as seen from the inside of the
mantle cavity. See abbreviations to the text-figures p. 102. Scale = 0.1mm.

This species occurs at upper to mid slope depths in the tropical
western Atlantic in the Brazil, Guyana, Caribbean and Gulf of
Mexico Basins (Dall, 1889; James 1972). Depth range; 943—2500m.

The holotype for 7: agatheda was not designated by Dall (1890),
nevertheless he did illustrate the left valve from Albatross Sta. 2754,
11°40'N 58°33'W (USNM 95437) which we have here nominated as

JUTE

lectotype. We have redrawn the shell and added detail of the hinge
plate (Figs 24 and 25). In addition, James (1972) reported that two
valves of T. agathedawere included in USNM 63149 from Blake sta.
236, 2909m off Bequia, furthermore USNM 94326 from Blake stas
26 and 30 between Cuba and Yucatan, identified by Dall as Leda
pusio, are examples of T. agatheda.

SHELL DESCRIPTION (Figs 24 & 25)

Shell small, sub-ovate, wide, sub-rostrate, ornamented with con-
centric ridges, postero-lateral furrow ventral to sub-rostrum,
ill-defined lunule outlined by obscure ridge, escutcheon similarly
ill-defined and bounded by faint ridge; umbo prominant, poste-
rior to mid-line, inwardly directed; antero-dorsal margin concave,
with change in slope at anterior limit of hinge plate, slightly
flattened anteriorly dorsal to the anterior limit of shell, antero-
ventral and ventral margins smoothly curved, postero-ventral
margin slightly sinuate, posterior margin acutely angled, postero-
dorsal margin slightly concave, marked angle at posterior limit of
hinge plate and thereafter almost straight to form sub-rostrate
posterior margin; anterior and posterior limits of shell are ventral
to horizontal mid-line; hinge plate strong, with edentulous space
ventral to umbo, hinge teeth stout, chevron-shaped, up to 12 in
each series in shell 6mm total length; internal ligament small,
close to shell margin, external ligament amphidetic, moderately
short, stout.

Young shells are less rostrate, with the posterior and anterior
limits of the shell more dorsal in position.

Although there is variation in the shape of the shell, the height/
length and the post-umbonal length/total length ratios increase
slightly with increasing size (Table 1). The maximum total length of
the present specimens is 6.0mm.

Fig. 24. Tindariopsis agatheda. External lateral view of the right valve of the lectotype and an internal view of the hinge plate of the same valve, from
U.S.Fish Commission station 2754 East of Tobago, USNM 95437. Scales = 1mm.

118

J.A. ALLEN AND H.L. SANDERS

Fig. 25.

Tindariopsis agatheda. External lateral views of right side of two specimens of differing size to show change in shape with growth. a, from Knorr

station 301 and b, from Knorr station 293, both from the Guyana Basin; c, external dorsal view of a shell also from station 293. Scale = 1mm.

Table 1. Measurements and ratios of shell parameters of the sample from
Knorr sta. 293.

Length (L) Height (H) Post-umbonal (PL) PL/L H/L
(mm) (mm) length (mm)

6.00 4.95 3.00 0.50 0.83
5.60 3.95 2.65 0.47 0.71
5.00 3.65 2.20 0.44 0.73
4.90 3.65 2.05 0.42 0.75
4.70 3.15 1.95 0.42 0.67
4.50 3.10 1.85 0.41 0.69
4.45 3.20 1.85 0.42 0.72
3.70 255 1.70 0.46 0.69
3.45 2.50 1.45 0.42 0.73
DBS) 1.58 0.93 0.39 0.67
2.05 1.43 0.93 0.45 0.70
1.95 1.30 0.88 0.45 0.67
1.83 1.28 0.83 0.45 0.70
1.10 0.88 0.48 0.43 0.80

INTERNAL MORPHOLOGY (Fig.26)

The siphonal embayment is shallow and dorso-ventrally narrow. In
contrast, the feeding aperture is broad and well-supplied with radial
pallial muscles. The adductor muscles are small, the posterior
muscle is oval and the anterior muscle is circular in cross section.
The foot is large with a well-developed heel containing a large
‘byssal’ gland. The gland opens into the posterior limit of the pedal
groove via a small papilla. The anterior two-thirds of the margins of
the divided sole are broadly papillate. The palps are large with up to
25 ridges in the largest specimens. The gills are narrow ill-defined
with about 16 plates in the largest specimens.

The mouth lies close to the posterior face of the anterior adduc-
tor muscle. The oesophagus opens into a large stomach and style
sac. The hind gut passes posterior to the style sac and stomach to
the dorsal side of the viscera and thence across the right side of
the body where it forms 8 coils before returning along the same
path to the dorsal side of the viscera and from there through the
heart and then dorsal to the posterior adductor muscle to the anus.

Usually not more than six coils are visible, the others being
overlain by those to the outside of them. The form of the hind gut
is derived by 4 complete turns of the closely parallel anterior and
posterior lengths of the hind gut on the right of the body. This
particular disposition of the hind-gut is to be found in other
ledellids (e.g. L. ultima) and yoldiellids (e.g. Y. ella Allen, Sanders
and Hannah 1995) (Allen and Hannah, 1989; Allen, 1992; Allen,
Sanders and Hannah, 1995).

The nervous system is similar in its arrangement to that of other
deep-sea protobranchs, however the cerebral and visceral ganglia
are noticably smaller and the commissures much finer than observed
in other species.

Fig. 26. Tindariopsis agatheda. Internal morphology as seen from the
right side of a specimen from Knorr station 293. For identification of the
parts see text-figure 7, p. 106. Scale = 1mm.

:

|
:

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

Tindariopsis aeolata (Dall 1890)

TYPE SPECIMEN. Holotype, USNM 95436.

TYPELOCALITY. U.S. Fish Commission Sta. 2754, East of Tobago,
11°40'N 58°33'W, 1609m.

CITED SPECIMEN. BMNH 1995061.

Malletia (Tindaria?) aeolata Dall 1890, 252.
Tindaria (Tindariopsis) aeolata Dall 1898, 582.
Tindariopsis aeolata James 1972, 97, figs 57-59.

MATERIAL:

Cruise Sta Depth No _ Lat Long Date Gear
(m)

GUYANA BASIN

Knorr 25 299 1942-4 O7S5S.1'N 55°42.0'W 29.2.72 ES
2076

301 2487-5 08°12.4'N 55°50.2'W _29.2.72 ES

2500

The type specimen has been examined by us.

This species occurs from mid to lower slope depths in the tropical
western Atlantic in the Guyana and Caribbean Basins and the Gulf of
Mexico. Depth range: 1609-3466m.

SHELL DESCRIPTION (Figs 27 & 28)

Shell small, subquadrate, rostrate, ornamented with marked concen-
tric ridges; periostracum pale yellow; umbos moderately large,
posterior to midline (post-umbonal length 45-48% of total length),
facing inwards, slightly separated by external ligament; distally
antero-dorsal shell margin horizontal, then curves smoothly and
steeply to anterior margin, postero-ventral margin sinuous, ventral
margin somewhat flattened, postero-dorsal distal margin slopes
gently to limit of hinge plate then curves sharply to rostral point,
latter rounded and somewhat eroded in large specimens, more
pointed in smaller, rostrum in mid horizontal plane in small speci-
mens and dorsal to it in large specimens, limit of anterior margin

Fig. 27. Tindariopsis aeolata. External lateral view of the right valve and
the hinge plate of the left valve of the holotype, from U.S. Fish
Commission station 2754, USNM 95436. Scale = 1mm.

119

C

Fig. 28. Tindariopsis aeolata. External lateral views of the right side of
shells of differing size to change in shape with growth. a, from Knorr
station 301 and b, from Knorr station 299 from the Guyana Basin; c,
external dorsal view of a shell also from Knorr station 299. Scales
= |mm.

ventral to the mid horizontal plane; hinge plate stout, small edentu-
lous space between tooth series, 9 chevron-shaped teeth in anterior
series and 10 in posterior series in largest specimens; ligament
amphidetic, external except for small resilifer at margin ventral to
umbo, external part thickened, particularly so in large specimens.
The maximum length of the present specimens is 5.8mm.

In lateral view the rostrum, although dorsal to mid horizontal line,
is reminiscent of Ledella, while the robust external ligament is more
reminiscent of Spinula.

INTERNAL MORPHOLOGY (Fig.29)

The siphonal embayment is relatively shallow and the contained
siphon is similar to that of 7: acinula. The adductor muscles are
moderately small, ovate in cross-section and equal in size. The foot
is large, with a divided sole fringed with large papillae. The “byssal’
gland is moderate in size. The palps are very large with many ridges
(c 26 in the largest specimen) and the palp proboscides are broad.
The gills are small with 11 gill plates in the largest specimen. The
kidney is long and narrow. The nervous system is of typical
protobranch design. The ganglia are relatively large and, in contrast,
the commissures are unusually slender.

The mouth lies some distance posterior to the anterior adductor
muscle (see below). The oesophagus opens on to the anterior face of
a moderately large stomach. The latter lies almost vertical within the
posterior part of the visceral mass. The hind gut is very small in
diameter and takes an extraordinarily complex course through the
body. There are two loops to the left side of the body (Fig.29B) and
one major loop to the right side of the body, all three pass from one
side to the other ventral to the umbo. There is also a complex series
of loops anterior and to the right of the stomach. This morphology
has not been encountered before in the protobranch bivalves and is
very different from that seen in 7: agatheda. Yet, it is debateable

120

Fig. 29. Tindariopsis aeolata. a, internal morphology as seen from the
right side of a specimen from Knorr station 301 from the Guyana Basin;
b, the form of the hind gut on the left side of the body. For identification
of the parts see text-figure 8, p.. Scale = 1mm.

whether the difference warrents generic status. Other protobranch
genera show an array of hind gut morphologies (e.g. Yoldiellidae,
Allen, 1992; Allen, Sanders and Hannah, 1995) which we believe
relate to changes in the benthic food resource as depth increases. For
this reason we are reluctant to erect a new genus when in other
respects T: aeolata is clearly within the genus Tindariopsis.

Subfamily Nuculaninae Allen and Sanders 1982

The subfamily is defined by Allen and Hannah (1986) and comprises
three genera Nuculana, Propeleda and Adrana.

Genus NUCULANA Link 1807

TYPE SPECIES.
77/2), OD);
Shell robust, moderately elongate, concentric sculpture, occa-
sionally with radial ribs, slightly rostrate, usually bicarinate; umbo
anterior; postero-dorsal margin straight or somewhat concave, pos-
terior margin may be slightly sinuous; escutcheon present; no
internal ridge from umbo to posterior margin; hinge moderately
robust, teeth chevron-shaped; ligament small, for most part internal,
usually amphidetic and vertical, sometimes posteriorly oblique.

Arca rostrata Gmelin 1791 = Arca pernula Miller

Genus PROPELEDA Iredale 1924

TYPE SPECIES. Leda ensicula Angas 1877. OD.

Shell very elongate, thin, glossy, concentric sculpture may be ill-
defined, 3/4 shell post-umbonal, usually with two marked carinae
from umbo to upper and lower limit of rostrum, posteriorly truncate;
umbo small; postero-dorsal margin concave, postero-ventral margin
not sinuous; internal ridge usually from umbo, skirts ventral margin
of posterior adductor to posterior margin, second ridge may be
present from hinge plate to rostral margin; hinge plate slender, hinge

J.A. ALLEN AND H.L. SANDERS

teeth chevron-shaped, one or both arms of the chevron may be
elongate, anterior tooth series curve round the outer margin of the
anterior adductor, posterior series extends posterior to adductor;
ligament in large part internal, opisthodetic and oblique.

Genus ADRANA Adams & Adams 1858

TYPE SPECIES. Nucula lanceolata Lamarck 1819. SD Stoliczka
1871.

Shell extremely elongate, slender, lanceolate, fragile, smooth or
with fine concentric and sometimes oblique sculpture, without
carinae, glossy; umbo almost central, barely raised; escutcheon
elongate, flattened, narrow; postero-dorsal margin straight, antero-
dorsal margin slightly convex, postero-ventral margin sinuous; hinge
plate slender, hinge teeth fine, obtuse, chevron-shaped; chondrophore
present; ligament internal, amphidetic.

Nuculana acuta (Conrad 1831)

TYPE SPECIMEN. Lectotype here designated, chosen from ANSP
30613, remainder of lot designated paralectotypes.

CITED SPECIMEN. BMNH 1995055.

TYPE LOCALITY. Tertiary fossil beds, near Suffolk, Virginia.

Nucula acuta Conrad 1831, 32, pl.6, fig.1.

Nucula cuneata Sowerby 1833, 198.

Nucula carinata H.C.Lea 1843, 163, (non M’Coy 1844).
?Leda jamaicensis d’ Orbigny 1846, 263, pl.XXIV, figs 30-32.
?Leda inornata A.Adams 1856, 48.

Leda unca Verrill 1880, 401, (2non Gould 1862).

Leda acuta Dall 1886, 251, pl.7, figs 3a, 3b and 8.

Nuculana acuta Morris 1951, 7, pl.6, fig.2.

MATERIAL:

Cruise Sta. Depth No Lat Long Date Gear
(m)

NORTH AMERICA BASIN

Atlantis Cl 97 2+2v 4020.5'N 7047.0'W 25.5.61 AD

264

Atlantis Slope 200 8+6v 40°01.8'N 7042.0'W 28.8.62 AD

283 sta.2

AtlantisI] 114 197 8 40°04.1'N 7027.8'W 15.8.66 ES

24

AtlantisII 172 119 7+2v 40°12.3'N 7044.7';W 27.11.67ES

40 3 2s) 4 40°10.8'N 70°43.6'W 28.11.67 ES

The type specimens have been examined by JAA.

Conrad (1831) described this species from fossils obtained from
the Miocene beds near Suffolk and the banks of the James and York
rivers, Virginia. He later redescribed the species (Conrad, 1845)
adding that he had found Recent specimens in deep water in the Gulf
of Mexico. His first account refers to specimens being in ‘Cabinet of
the Acad. Nat. Sciences, No.1738. This reference does not corre-
spond with any lot of N. acuta, Recent or fossil, in the Academy of
Natural Sciences, Philadelphia today. There are specimens in the
Invertebrate Paleontology collection of the Academy (catalogue
number 30613) that up to now have been considered as possible
syntypes of the species. The lot comprises 4 right valves, 3 left
valves | left and | right broken valve, | intact shell, 1 shell with
rostrum tip missing and 3 fragments. These specimens, labelled by

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

121

Fig. 30. © Nuculana acuta. a & b, lateral and dorsal external views of the lectotype, ANSP 30613; c, lateral internal view of a paralectotype from the same

lot. Scales = 1mm.

Conrad, may include those figured by him. Comparison with the
figures (Conrad, 1831 and 1845) shows that it is impossible to say
which, if any one, was figured nor is it possible to be absolutely
certain that these are the specimens from which the original descrip-
tion was made, although we believe that they are. Thus, the intact
shell from lot 30613 has been chosen as the lectotype, the remainder
being paralectotypes.

Campbell (1993) listed Leda jamaicensis d’Orbigny 1846, Leda

Fig. 31. Nuculana acuta. Lateral and dorsal external views of a shell,
from Atlantis 283 station 2 from the North America Basin. Scales =
Imm.

inornata A.Adams 1856 and L.unca Gould 1862 as synonyms of N.
acuta. Verrill (1882) describes in detail differences that he found
between N. acuta and L.jamaicensis and L.unca which cast doubt as
to the synonymy, although Dall (1886) maintains the synonymy of
L. jamaicensis. Similarly, we have doubts as to synonymy with
L.inornata A.Adams which is a “gibbose’, “fuscous’, ‘sulcate’ spe-
cies from New Guinea, Thus, although Nuculana acuta is a
well-described species (e.g. Verrill 1882, 1884; Dall, 1886; Abbott,
1974) because there are closely related species in the Atlantic and
elsewhere, we include a description here. It occurs off the East coast
of North America, in the Caribbean Sea and off Brazil at depths from
the outer shelf to lower slope depths, 97-2909m (James, 1972).

SHELL DESCRIPTION (Figs 30, 31)

Shell moderately large, elongate, somewhat inflated, rostrate,
ornamented with deep concentric ridges flattened at the apex, rostral
ridge from umbo to ventral limit of rostrum, very faint radial ridge
from umbo to antero-ventral margin, yellow periostracum; lunule

Fig. 32. Nuculana acuta. Internal morphology as seen from the right side
of a specimen from Atlantis II station 197 from the North America Basin.
For identification of the parts see text-figure 7, p. 106. Scale = 1mm.

122

SP

ize)
=o]

IDS

J.A. ALLEN AND H.L. SANDERS

AN se
PSEA i MM
==Zea i
Es BEZE 2
—= Ea :
\ \
a oe ow PE

—

wl Mi

=
G@

=e

Fig. 33. Nuculana acuta. Internal morphology, a, anterior, b, left lateral & c, posterior views of a dissected stomach and combined style sac; d, ventral
view of siphonal region. See abbreviations to text-figures on p. 102. Scales = 1mm.

broad, elongate, outlined with faint ridge, escutcheon broad, out-
lined by rostral ridge; umbos small, inwardly directed, anterior to
mid-line; antero-dorsal margin broadly concave, anterior, antero-
ventral, ventral and postero-ventral margins form smooth curve,
postero-dorsal margin raised, distally straight, proximally — poste-
rior to hinge plate — slightly concave, may be slightly upturned in
larger specimens; hinge plate elongate, relatively broad, hinge teeth
chevron-shaped, up to 18 teeth in each series depending on size of
specimen; ligament small, amphidetic, internal pear-shaped in sag-
ittal section, extends slightly ventral to hinge plate. The maximum
length of the present specimens is 9.2mm.

INTERNAL MORPHOLOGY (Figs 32, 33)

The siphonal embayment is deep, with an elongate tentacle attached
to the inner right or left side. The siphons are elongate, combined
and except anteriorly, the ventral margins are fused. In the con-
tracted state the line of fusion is marked by deep ventral furrow. The
anterior sense organ is far anterior, situated at the point where the
radial ridge meets with the shell margin. Between the feeding
(ventral to the siphonal embayment) and the pedal gape, the inner

folds of the ventral margin are applied to each other. In this section
of mantle margin approximately 30 small sensory papillae are
attached to each middle sensory fold in a specimen 6.5mm total
length. The adductor muscles are small the anterior unusually so.
The anterior adductor is circular in cross-section and the posterior
elongate-oval.

The foot is moderately large, elongate, the sole with papillate
margins. The heel is not marked but there is a a large “byssal’ gland
present internal to the posterior limit of the sole. The gills are well-
developed with up to 48 alternating gill plates. The dorsal margins of
the left and right inner demibranchs are fused. In life the gills are a
bright orange-red colour. In contrast the palps are cream. The latter
are relatively small, elongate and dorso-ventrally narrow and, for the
most part, hidden under a fold of the body wall. This latter is more
pronounced on the right side of the body where the hind gut loop
meets the ventral margin of the visceral wall. Each palp has up to 24
ridges on the inner face. The palp proboscides are also long and
tapering.

The digestive gland is bright orange in life. As in other species of
Nuculana, the course of the hind gut describes a single loop to the

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

right side of the viscera. There is a single typhlosole present along its
entire length. The stomach is of moderate size and internally is
similar in form to that of shallow water species of Nuculana (Yonge,
1939). The gastric shield lines much of the left wall of the stomach.
To the right there is a large posterior sorting area with 13 ciliated
ridges. A deep caecum is ventral to the oesophageal aperture. Two
digestive ducts open close to the antero-dorsal margin of the poste-
rior sorting area and a single duct opens antero-dorsally close to the
oesophageal opening.

As will be seen Nuculana acuta is remarkably similar in its shell
features and anatomy to Nuculana commutata. This similarity is
discussed under the latter species (p. 123).

Nuculana commutata (Philippi 1844)

TYPE SPECIMEN. ZMHU.

TYPE LOCALITY. Pliocene, Palermo, Sicily.

CITED SPECIMEN. BMNH 1995212

Arca fragilis Chemnitz 1784, 199, pl.LV, fig.546.

Arca pella Gmelin 1790 (non Linné), 3307.

Arca minuta Brocchi 1814 (non Fabricius), 482, pl.XI,fig.4.

Nucula pella Payraudeau 1826 (non Linné), 64.

Lembulus deltoideus Risso 1826 (non Lamarck), 320, pl. XI, fig.
164.

Nucula minuta Scacchi 1836 (non Fabricius), 4.

Nucula striata Philippi 1836 (non Lamarck), 64.

Nucula commutata Philippi 1844, 101.

Leda fragilis Jeffreys 1879, 575.

Leda minuta Jeffreys 1856 (non Fabricius), 25.

Leda commutata Hanley 1863, pl.CCXVIII, figs, 80, 81.

Lembulus commutatus Monterosato 1878, 6.

Leda (Portlandia) tenuis Sturany 1896, 6.

Nuculana (Jupiteria) fragilis Nordsieck 1969, 9, pl.I, fig.02.25.

Nuculana (Jupiteria) commutata Smith and Heppell 1991, 56.

MATERIAL:

Cruise Sta Depth No Lat Long Date Gear

(m)

WEST EUROPEAN BASIN

Sarsia 829) 119 16 4740.0'N 05°00.0'W 12.8.67 ES

SHELL DESCRIPTION (Fig.34)

Shell moderately large, elongate, slightly inflated, rostrate,
ornamented with concentric ridges, pale straw-coloured perio-
stracum; radial ridge from umbo to antero-ventral margin; rostral
ridge well-defined, delimits posterior dorsal area, within this area a
faintly outlined escutcheon extending half the length of postero-
dorsal margin; lunule elongate, defined by fine ridge; less
well-defined ventral rostral ridge extends from umbo to postero-
ventral margin; umbos anterior to midline, inwardly directed;
antero-dorsal margin proximally straight, distally slightly concave
merging with rounded anterior margin to where it meets with ventral
limit of anterior radial ridge, ventral margin broadly concave, postero-
ventral margin sinuate where ventral rostral ridge meets margin,
posterior margin acute, slightly upturned, postero-dorsal margin
slightly raised with shallow angulation at limit of hinge plate; hinge
plate elongate, relatively broad, acute chevron teeth, 16 on both
anterior and posterior hinge plates of specimen 8.3mm total length;
ligament internal, amphidetic, triangular, extends slightly ventral to
hinge plate.

123

Fig. 34. Nuculana commutata. Lateral and dorsal views of a shell, from
Sarsia station $29 from the West European Basin. Scale = 1mm.
Maximum length of present specimens is 8.3mm.

INTERNAL MORPHOLOGY (Fig.35)

The internal morphology differs little from that of N. acuta (Fig.32).
The most noticable differences are that N. commutaia has less
attenuate palps with fewer palp ridges and larger adductor muscles
than does N. acuta.

Other differences between the two species are that inN. commutata
the ridge from the umbo to the antero-ventral margin is more
marked, the apices of the concentric ridges are less broad, the
postero-dorsal margin is not so raised and the shell is somewhat less
elongate in relation to its height.

These differences are of degree and at that point where separation
into species rather than subspecies is a subjective judgement. Never-
theless, these differences are more marked than those between N.
commutata andN. illiricaCarrozza 1987 (paratypes BMNH 1995213
examined by JAA), a species that has been recently described from
the northern Adriatic Sea (Carrozza, 1987). In contrast. commutata

Fig. 35. Nuculana commutata. Internal morphology as seen from the
right side of a specimen from Sarsia station $29 from the West
European Basin. For identification of the parts see text-figure 7, p. 106.
Scale = 1mm.

124

is widely distributed throughout the Mediterranean and lusitanean
Atlantic. Prior to the paper by Carrozza (1987) there had been debate
as to whether N. fragilis and N. commutata were the same species
(Locard, 1891, 1898; Bucquoy et al, 1887-98). It is not possible to
determine whether this earlier debate was a presage to the study of
Carrozza (1987). In contrast N. acuta is even more widely distrib-
uted off the eastern North America, West Indies and off Brazil
(Abbott, 1974). It must be assumed that these are three sibling
species.

Nuculana vestita (Locard 1898)

MNHN

TYPE LOCALITY. Talisman stas 96-98 & 101, West of Senegal,
2324-3200m, 19°12'N 17°57'W — 16°38'N 18°24'W

CITED SPECIMENS. BMNH 1995056 and 1995211

Leda vestita Locard 1898, 340, pl.XIV, figs 12-18

Nuculana vestita Clarke 1962, 53.

Leda macella Barnard 1963, 448, fig.11d; type locality: West off
Cape Point, S.W.Africa, Africana II stas A190, A192, A317,
A319, 2268—3200m, SAM (not seen).

TYPE SPECIMEN.

MATERIAL:
Cruise Sta Depth No Lat Long Date Gear
(m)
SIERRA LEONE BASIN
AtlantisI] 146 2842 1 10°39.5'N 1744.5'W 6.2.67 ES
31 —2891
ANGOLA BASIN
Atlantis11 201 1964 1 09°29.0'S. 1134.0'E 23.5.68 ES
42 —2031
203 527 742 0846.0'S 12'47.0'E 23.5.68 ES
—542

J.A. ALLEN AND H.L. SANDERS

Specimens taken by the Galathea Expedition described by
Knudsen (1970) examined by JAA, ZMUC. Knudsen (1970) fol-
lowing examination of specimens synonymized L. macella with N.
vestita.

Nuculana vestitais a well-described species (Locard, 1898; Theile
and Jaeckel, 1931; Knudsen, 1970) occurring off West and South-
west Africa at lower slope depths (715—2891m) in the Sierra Leone,
Guinea and Angola basins.

SHELL DESCRIPTION (Figs 36 & 37)

Shell moderately large, inflated, somewhat elongate, rostrate,
ornamented with concentric ridges, pale brownish-yellow
periostracum; umbos large, inwardly directed, anterior to midline;
antero-dorsal distal margin horizontal for short distance, proximal
margin broadly convex forming smooth curve with anterior margin,
ventral margin broadly convex to rostrum, postero-dorsal margin,
raised in small specimens but less so in large, proximally straight or
slightly concave, in small specimens angulate at limit of posterior
hinge plate, distally slightly concave to posterior limit of rostrum;
broad ridge extends from umbo to rostrum forming outer limit of
escutcheon; anterior and posterior hinge plates broad, meet shell
margin ventral to umbo, hinge teeth broad chevrons, up to 19 and 16
in anterior and posterior series respectively in specimen 8.3mm total
length; ligament internal, amphidetic, pear-shaped in sagittal verti-
cal section, extends ventral to hinge plate. The maximum length of
the present specimens is 13.8mm.

INTERNAL MORPHOLOGY (Fig. 38)

The adductor muscles are moderately large and oval. The siphonal
embayment is deep with the siphonal tentacle to the right side. The
siphons are entire. The feeding aperture is small but well-defined
with the mantle surface ridged internally. Radial mantle muscles
are well-developed forming a broad band internal to the inner lobe

Fig. 36. Nuculana vestita. External right lateral and dorsal view of a large adult shell and a lateral view of the hinge plate of a right valve. Specimens are

from Atlantis II station 203 from the Angola Basin. Scale = Imm.

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

125

Fig. 37. Nuculana vestita. Lateral views of right side of four shells in outline to show differences in shape with increasing size. Specimens from Atlantis

II station 203 from the Angola Basin. Scale = 1mm.

of the mantle edge. The anterior mantle sense organ is well-
developed.

The foot is large with the margins of the sole finely papillate. The
palps are very small with up to 12 broad folds. The palp proboscides
are stout and elongate, even in the contracted state. The gills are
elongate and broad with up to 36 gill plates.

Propeleda carpenteri (Dall 1881)

TYPE SPECIMEN. Syntypes, USNM 63151 and MCZ 7936-7938.

TYPE LOCALITY. Off Barbados, ‘Blake’ stations 5, 9, and 21,

100fm—287fm.
CITED SPECIMENS. BMNH 1995057

Leda carpenteri Dall 1881, 125; 1886, 249, pl.8, fig.10, pl.9, fig.3.
Nuculana carpenteri Johnson 1934, 16.

MATERIAL:
Cruise Sta. Depth No Lat Long Date Gear
(m)
ARGENTINE BASIN
AtlantisII 237 993- 194 3632.6'S 53°23.0'W 11.3.71 ES
60 1011
239 =1661- 8 S64910S 53154 W 11371) ES
1679
240 2195- 8 3655'4'S_ 59 LO2W 312-371) ES
2323

Specimen USNM 63151 examined by JAA.

Previously reported off N. Carolina, Gulf of Mexico and Eastern
Caribbean (Dall, 1889; Rice and Kornicker, 1965; James, 1970), the
present specimens are from the Argentine Basin. This species has a

ZZ

ZE
ZA
re

Fig. 38. Nuculana vestita. Internal morphology as seen from the right
side of a specimen from Atlantis II station 203 from the Angola Basin.
For identification of the parts see text-figure 7, p. 106. Scale = imm.

somewhat unusual distribution from shelf to lower slope depths,
200-2323m

SHELL DESCRIPTION (Figs 39-41)

Shell fragile, semi-transparent, slender, moderately elongate, rostrate
with two post umbonal carinae, ornamented with faint concentric
ridges; periostracum pale straw colour; umbos small, far anterior
(postumbonal length 60-68% of total length), inwardly facing;
antero-dorsal margin slightly flattened, ventral margin smoothly
curved, postero-dorsal margin raised, slightly sinuous, concave
proximally, convex distally, meets posterior margin at limit of dorsal
post-umbonal carina, posterior margin concave between posterior

126

J.A. ALLEN AND H.L. SANDERS }
|
|

i]

+-—__—

Fig. 39. Propeleda carpenteri. External lateral view of the left valve and an internal view of the same valve of a syntype USNM 63151, from off

Barbados in 100fms. Scale = 1mm.

limits of dorsal and ventral carinae; escutcheon lanceolate; hinge
plates relatively broad, posterior plate short, occupying little more
than half of postero-dorsal margin, anterior plate approximately half
length of posterior, hinge teeth acute chevron-shape, relatively few
in number, up to 18 in posterior series and 16 in anterior; ligament
internal, oblique, posterior to umbo; internal shell ridge extends
from mid posterior margin to approximately opposite the mid-point
of the posterior hinge plate between and parallel to the lines of the

(

KUT

OMA
Xd

((

~

post-umbonal carinae.The maximum length of the present speci-
mens is 15.3mm.

In most specimens the posterior shell margin is damaged, often
being markedly shortened and specimens frequently show regenera-
tion of the shell posterior to the posterior adductor. The repaired
shell is without concentric ornamentation. It is possible that ex-
tended siphons are predated upon and that the shell is damaged when
this occurs.

Fig. 40. Propeleda carpenteri. External lateral view of the right side of a shell and an internal lateral view of a right valve from Atlantis II station 237

from the Argentine Basin. Scale = 1mm.

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

Fig. 41. Propeleda carpenteri. External lateral views of the right sides of
two small shells to show differences in shape from the specimen
illustrated in text-figure 40. Specimens taken from Atlantis II station 239
from the Argentine Basin. Scale = 1mm.

The concentric ridges on the shell of the present specimens while
not particularly marked are more so than those described by Dall,
though the syntypes that we have examined are dead valves that are
somewhat worn (Fig.39). Our specimens also are very slightly more
anteriorly extended than the syntypes, though the characteristic
antero-dorsal curvature of the shell margin is the same. Our speci-
mens correspond well with the figures given by James (1972, figs 67
and 68). These latter come are from similar depths (2340—2627m) to
some of our own. It would appear that specimens from mid to lower
slope differ slightly from those taken at shallower depths however,
we regard the differences as being at most infrasubspecific.

There is a marked change in shape during growth. Juveniles are
much shorter than the adults and subsequent growth involves in-
creasing elongation of the post-umbonal shell. The prodissoconch is
extremely large measuring 630m in length.

127

INTERNAL MORPHOLOGY (Fig.42)

The adductor muscles are oval in cross-section, the posterior being
the more fusiform, both are set some distance in from the shell
margin. The posterior adductor muscle lies opposite the limit of the

posterior hinge plate, the anterior muscle is attached to the shell just
dorsal of the mid-horizontal shell axis. The siphonal embayment is
elongate, the siphons are slender and entire. The anterior sense organ
is small in size.

The foot lies in the anterior half of the mantle cavity in preserved
specimens, it is relatively elongate and has numerous small papillae
present along the margins of the sole. The palps are small, each
bearing an extremely long, narrow, palp proboscis. Depending on
the size of the specimen there are up to 17 palp ridges. The gills are
elongate, slender, and have up to 17 plates.

The course of the hind gut is similar to that in Nuculana in that it
passes to the right side of the body where it forms a broad loop that
passes close to the posterior wall of the anterior adductor muscle.
The stomach is large and occupies a vertical position in the posterior
part of the visceral mass. The digestive gland is extensive occupying
much of the antero-dorsal visceral space.

Propeleda louiseae (Clarke 1961)

TYPE SPECIMEN. Holotype, MCZ 224958.

TYPE LOCALITY. R.V.Vema biology station 121, Argentine Basin,
1000 miles ESE of Buenos Aries, 5105 metres.

BMNH 1995058
Nuculana (Thestyleda) louiseae Clarke 1961, 375, pl.1, fig. 7.

CITED SPECIMENS.

MATERIAL:
Cruise Sta’ Depth No Lat Long Date Gear
(m)
ARGENTINE BASIN
AtlantisII 242 4382— 25 3816.9'S 51°56.1'W 13.3.71 ES
60 4402
243, 3815= 2 3736.8'S 52°23.6'W 14.3.71 ES
3822
247 5208- 2 43°33.0'S 48°58.1'W_17.3.71 ES
5223
256 3906- 3 3740.9'S_ 52°19.3'W_24.3.71 ES
3917

Fig. 42. Propeleda carpenteri. Internal morphology as seen from the right side of a specimen taken from Atlantis II station 239 from the Argentine Basin.

For identification of the parts see text-figure 7, p. 106. Scale = 0.5mm.

128

SS

Ba

J.A. ALLEN AND H.L. SANDERS

ey

Fig. 43. Propeleda louiseae. a & b, external lateral views of the right sides of shells of differing size to show differences in shell proportions with growth;
note outline internal morphology through semi-transparent shells, in particular the form of the hind gut and position of the adductor muscles; c, outline of
shell from the left side showing the outline of hind gut and adductor muscles; d, internal view of a left valve. All specimens taken from Atlantis II station

242 from the Argentine Basin. Scales = 1mm.

Type specimen examined by HLS.
Distributed at abyssal depths in the Argentine Basin; depth range:
3815-5223 metres.

SHELL DESCRIPTION (Fig.43)
Shell extremely elongate, slender, fragile, semi-transparent,
ornamented with moderately spaced concentric ridges, two post-
umbonal rounded ridges, one dorsal and one ventral at posterior
shell margin and crossed vertically by wavy continuations of the
concentric ridges, faint anterior radial ridge from umbo to antero-
ventral margin; umbo slightly raised, far anterior (post-umbonal
length 65-70% of total length), inwardly facing; antero-dorsal
margin with short proximal notch, distally margin raised and slightly
concave, faint angulation before anterior margin, anterior margin
joins with ventral margin in smooth curve, postero-ventral margin
very slightly sinuate, posterior margin angled and sinuate, postero-
dorsal margin notched at umbo, distally somewhat raised and keeled,
concave overall but slightly sinuous dorsal to hinge plate; hinge
plate relatively broad, posterior plate short occupying approxi-
mately half the postero-dorsal shell margin, hinge teeth elongate,
acute chevron shape, up to 12 in anterior and 20 in posterior series;
ligament small, internal, oblique, pear-shaped; rounded internal
ridge extends from umbo to posterior margin and marks junction
between inhalent and exhalent siphons. The maximum length of the
present specimens is 20.3mm. The prodissoconch is large measuring
300um in length.

Clarke (1961) records a long, thin, external ligament in the type

specimen — the latter being a single large valve. We find no evidence
of an external part to the ligament and believe that Clarke mistakenly
confused periostracum along the postero-dorsal margin for liga-
ment.

INTERNAL MORPHOLOGY

With one notable exception the internal morphology of Plouiseae
differs little from that of P. carpenteri.

Unlike the latter species the hind gut of P. louiseae first passes to
the left side of the body where it forms a relatively small loop
immediately ventral to the umbo (Fig.43). From there it passes to the
right of the body and forms a loop that is considerably larger than
that on the left although not as extensive as that in P. carperteri (Figs
42 & 43).

The adductor muscles are relatively large, the elongate poste-
rior muscle is situated at the distal limit of the posterior hinge
plate. The gill is very short and slender with few (c. 13) gill-
plates.

Propeleda paucistriata (new species)

TYPE SPECIMEN.
1995060.

Holotype BMNH 1995059; Paratypes BMNH

TYPE LOCALITY. Atlantis II station 203, Angola Basin, 08°48.00'S
12'52.00'E, 527-542m.

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

MATERIAL:

Cruise Sta. Depth No _ Lat Long Date Gear
(m)

ANGOLA BASIN

AtlantisII 203 527— 31 0848.00'S 12°52.00E 23.5.68 ES

42 542

DISTRIBUTION. Restricted to the Angola Basin at upper slope

depths, 527-542 metres.

SHELL DESCRIPTION (Fig.44)

Elongate, fragile, transluscent shell, moderately slender, two cari-
nate ribs from umbo to posterior margin, widely spaced prominant,
relatively broad, concentric ribs with overhanging ventral margin,
2-4 fine concentric lines between ribs, between carinae vertical ribs
and lines equally prominant; umbo moderately raised, far anterior in
largest specimens (post-umbonal length 79% of total length) but less
so in smaller specimens, beaks inwardly facing; antero-dorsal mar-
gin sloping, proximally convex but almost straight in small specimens,
joins with anterior and antero-ventral margins in smooth curve;
postero-ventral margin very slightly sinuous, posterior margin usu-
ally damaged in large specimens, intact margin angled and sinuate,
forming a hook dorsally where postero-dorsal margin and dorsal
carina meet, postero-dorsal margin concave, proximally raised,
elongate escutcheon outlined by dorsal carina; hinge elongate,
moderately broad, large, acute chevron-shaped teeth up to 16 in
anterior series and up to 28 in posterior series, anterior series extends
to anterior limit of anterior adductor muscle, posterior series extends
approximately half length of postero-dorsal margin to anterior limit

129

of posterior adductor muscle, ventral margin of hinge plate corre-
sponds to line of dorsal carina, ventral to umbo teeth approach shell
margin, anterior and posterior hinge plates continuous; ligament
internal, ventral to umbo and close to shell margin, slightly inclined
posteriorly; rounded internal ridge extends from umbo to posterior
margin. The maximum recorded shell length is 14.1mm. The
prodissoconch is very large and measuring 560um in length.

Juvenile shells are more ovate and, before posterior elongation
occurs, could be mistaken for a yoldiellid (Fig.44).

INTERNAL MORPHOLOGY (Fig.45)

The anterior adductor muscle is oval in cross section, while the
posterior adductor is smaller and more elongate. Both are set in from
the shell margin, the posterior is positioned at approximately two-
thirds the distance between the umbo and the posterior limit of the
shell. There is a small anterior sense organ formed from the sensory
fold of the mantle, ventral to the anterior adductor. The siphons are
joined with their ventral margins fused to form entire lumina. They
are slender and particularly elongate and when contracted are con-
tained in the elongate siphonal embayment. The foot and viscera lie
in the anterior half of the mantle cavity. The foot is elongate and
directed anteriorly. In most preserved specimens the tip of the foot
lies between the anterior adductor and the shell margin. The margins
of the sole are fringed with numerous relatively small papillae.
There are three anterior and two posterior pedal retractor muscles.
The palps and gills are markedly narrow and elongate. The are at
least 22 palp ridges in the largest specimens and the palp probosci-
des are attenuate each with a straight dorsal margin and a papillate
ventral margin. In a few preserved specimens the palp proboscides
extend from the feeding aperture. The gills are similarly attenuate

Fig. 44. Propeleda paucistriata. External lateral views of the right sides of four shells of differing size to show change of shape with growth and an
internal view of a right valve. All specimens taken from Atlantis II station 203 from the Angola Basin. Scale = 1mm.

130

J.A. ALLEN AND H.L. SANDERS

Fig. 45. Propeleda paucistriata. a, internal morphology as seen from the right side; b, part of the left side of the same specimen to show details of the
course of the gut; c, the internal morphology as seen from the left side of a much larger specimen. All specimens taken from Atlantis II station 203 from
the Angola Basin. For identification of the parts see text-figure 7, p. 106. Scales = 1mm.

and extend from the posterior visceral mass to the anterior limit of
the posterior adductor. There are at least 22 gill plates in larger
specimens. A slender extension of the axis extends from each gill
from ventral to the posterior adductor to the inner junction between
inhalent and exhalent siphons.

From the large combined stomach and style sac the course of the
hind gut takes it first dorsal and posterior to the stomach and then to
the left side of the body where it makes a small loop. From there it
passes ventral to the umbo to the right side of the body where it
makes a much larger loop at the perimeter of the viscera and passing
close to the inner face of the anterior adductor. From there it passes
mid-dorsally to the anus. The mouth is set some distance posterior to
the anterior adductor muscle. The oesophagus is broad and elongate
and the combined stomach and style sac is positioned vertically in
the posterior part of the visceral mass. The pedal ganglion is large
and lies immediately anterior to the junction of mid gut and hind gut.

The shell surface in some larger specimens is covered with
epifaunal solitary hydroids. This would indicate that P. paucistriata
lives close to the surface of the sediment. This is also suggested by
the fact that the posterior tips of the shells of larger specimens are
broken. We believe that this is the result of predation on the siphons.

The extreme post-adductor elongation of the shell is advanta-
geous in that it provides distance between predator and the more
vulnerable viscera with damage being restricted to more easily
generated tissue.

The shell of this species differs from others described by the small
number of pronounced concentric shell ridges and we name it with
reference to this characteristic feature. This is the first species of
Propeleda to be recorded off the south-west coast of Africa. At
approximately the same latitude off the east coast of Natal a species
named Leda lancetaby Boshoff (1968) occurs at upper slope depths.
Nijssen-Meyer (1972) believes that this latter species is a Propeleda,

and we concur with her. P. /anceta is more robust, more arcuate and
with far more numerous concentric ridges than is the case in P
paucistriata.

DISCUSSION

The major point of interest in this particular account of deep-sea
protobranch bivalves is the evidence it provides to further our
understanding of the evolution of the nuculanoid protobranchs. In
our earlier studies on the Tindariidae we speculated as to how the
nuculanoids could have evolved from the nuculoids (Sanders and
Allen, 1977). In functional terms, this involved a change in the
inflow of water into the mantle cavity from an antero-ventral posi-
tion to a posterior position and the begining of specialization of the
posterior mantle edge, a view also expressed by Yonge (1939). In the
tindariids this latter involves the development of sensory papillae
from the sensory fold of the mantle at the points of ingress and exit
of the circulatory water. Although infaunal and deposit feeding, the
tindariids, like the nuculids, live close to the surface and, like many
other bivalves that occupy this position, they are ovate and robust.
Many of these subsurface dwelling bivalves, including the tindariids,
have stout external ligaments.

The development of siphons was the next step in the evolutionary
process and the neilonellids are illustrative of this. The shell form and
ligamentas seen in the tindariids is largely retained in the neilonellids,
but short siphons, as yet only fused dorsally, are now present and these
are contained in a shallow siphonal embayment. Although the shell
remains stout and ovate there is some posterior elongation and an area
ventral to the inhalent siphon from where the palp proboscides are
extended is more defined. Like the tindariids the neilonellids are
deposit feeders living close to the surface of the sediment.

DEEP-SEA PROTOBRANCHIA (BIVALVIA)

The hind gut in Neilonella, like that in Tindaria, has a wide lumen
and single pronounced typhlosole. Although the course that the hind
gut takes in neilonellids makes a single loop on the right side of the
body, it does not penetrate mantle space as it does in tindariids
(Sanders andAllen, 1977). In this respect the hind gut of neilonellids
probably represents the more primitive condition. We have argued
elsewhere (Allen, 1992) that elongation and the complexity of form
of hind gut configuration are related to food procurement at great
depths, and this applies to the tindariids (Sanders and Allen, 1977).
The neilonellids are for the most part upper slope species and the
hind gut would be expected to be less specialized and less elongate.

In Nuculana posterior elongation becomes more extreme and the
ventral margins of the combined siphons are fused such that the
exhalent and inhalent lumena are separate and entire. The shell
remains robust, but is more slender The ligament is restricted to a
small internal structure separating elongated anterior and posterior
series of hinge teeth. We believe that elongation is correlated to the
almost vertical orientation of the animal in the sediment but which
retains contact with the surface via the extended posterior body and
siphons. The genus Nuculana is found mainly in shelf and upper
slope sediments and as such the available food resources are rela-
tively abundant. The hind gut is not greatly extended and remains as
a single loop to the right side of the body.

In Propeleda the evolutionary trend of posterior body elongation
seen in Nuculana becomes is more extreme, particularly posterior to
the posterior adductor muscle. The posterior adductor muscle is
more elongate and dorso-ventrally narrow, and the gill, gill axes,
siphons and the palp proboscides are exceptionally long and slender.
The shell of Propeleda, particularly in abyssal species, is much more
fragile and is further specialized in that it possesses an internal
posterior longitudinal ridge. The function of this ridge is not entirely
clear and has await examination of the living animal but, possibly, it
is involved in the separation of excretion, feeding and respiratory
functions in the extremely elongate posterior mantle cavity. It may
also help to strengthen the otherwise very fragile shell and assist in
predation damage limition. In Propeleda post-adductor elongation
involves body tissues that can be relatively easily regenerated, much
in the same way as has been reported in deposit feeding tellinids
(Edwards, Steele and Trevallion, 1970). Specimens showing shell
repair posterior to the posterior adductor are present in our samples.

The evolution of the Ledellinae and an assessment of their func-
tional morphology was discussed earlier (Allen and Hannah, 1989).
In respect of the species of Ledella and Tindariopsis described here,
little needs to be added to that account other than to note, again, that
the hind gut in these abyssal protobranchs is extraordinarily length-
ened and takes the most complex courses within the visceral mass.

The other item of note is the description of yet another ledellid in
which the shell, after reaching a certain length, changes its direction
of growth. In Ledella aberrata as in L. ultima the result of this
change is to produce a broad shell margin and lateral expansion of
the shell cavity. This adaptation has been construed as possibly
providing more space for the gonads that begin to develop at about
the time the change in direction occurs.

ACKNOWLEDGEMENTS. It is fitting that in this paper we thank our numer-
ous friends and colleagues, particularly French colleagues of the Biogas and
Walda cruises, who provided much material and gave much advice and
encouragement. We would like to mention three colleagues by name. George
Hampson of the Woods Hole Oceanographic Institution and Fiona Hannah
(Lonsdale) of the University Marine Biological Station, Millport, who have
given us tremendous close support over the years and without their help it is
likely that we would not have succeeded in this task within our lifetimes, and
Kathy Way of the Natural History Museum, London, who has been so quick

Si

in responding to our requests for help particularly in our quest for early
literature and specimens for comparison. Much of the work was supported by
grants from the Natural Environment Research Council.

REFERENCES

Abbott, R.T. 1974. American Seashells. Van Nostrand Reinhold, New York.

Allen, J.A. 1992. The evolution of the hindgut of the deep-sea protobranch bivalves.
American Malacological Bulletin, 9: 187-191.

Allen, J-A. and Hannah, F.J. 1986. A reclassification of the Recent genera of the
subclass Protobranchia (Mollusca: Bivalvia). Journal of Conchology, 32: 225-249.

Allen, J.-A. and Hannah, F.J. 1989. Studies on the deep sea Protobranchia: the
subfamily Ledellinae (Nuculanidae). Bulletin of the British Museum of Natural
History (Zoology), 55: 123-171.

Allen, J.-A. and Sanders, H.L. 1973. Studies on deep-sea Protobranchia (Bivalvia): the
families Siliculidae and Lametilidae. Bulletin of the Museum of Comparative Zool-
ogy Harvard, 145: 263-310.

Allen, J.A. and Sanders, H.L. 1982. Studies on the deep-sea Protobanchia, the
subfamily Spinulinae (family Nuculanidae). Bulletin of the Museum of Comparative
Zoology Harvard, 150: \-30.

Allen, J.A., Sanders, H.L. and Hannah, F.J. 1995. Studies on the deep-sea
Protobranchia (Bivalvia); the subfamily Yoldiellinae. Bulletin of the British Museum
of Natural History (Zoology), 61: 11-92.

Boshoff, P.H. 1968. Descriptions of three new species of Pelecypoda dredged off the
coast of Natal, South Africa. Transactions of the Royal Society of South Africa, 38:
95-98.

Brugnone, J. 1876. Miscellanea Malachologica. Pars secunda. Typographia Lao,
Panormi.

Bucquoy, E., Dautzenberg, P. and Dolfuss, G. 1887-98. Les mollusques marins du
Roussillon, I, Pelecypoda. Bailliere, Paris.

Campbell, L.D. 1993. Pliocene molluscs from the Yorktown and Chowan River
formations in Virginia. Virginia Division of Mineral Resources, Publication 127, 1—
259.

Carrozza, F. 1987. A new marine bivalve species from the Mediterranean: Nuculana
illirica spec. nov. (Bivalvia: Palaeotaxodonta: Nuculanoidea). Basteria, (1987),
159-161.

Clarke, A.H.Jr. 1961. Abyssal mollusks from the south Atlantic Ocean. Bulletin of the
Museum of Comparative Zoology Harvard, 125: 345-387.

Conrad, T.A. 1831. American Marine Conchology; or descriptions and coloured
figures of the shells of the Atlantic coast of North America. Philadelphia.

Conrad, T.A. 1838-1861. Fossils of the [Medial Tertiary or] Miocene Formation of the
United States. Dobson, Philadelphia.

Dall, W.H. 1881. Reports on the results of dredging, under the supervision of Alexan-
der Agassiz, in the Gulf of Mexico, and the Caribbean Sea, 1877-79, by the United
States Coast Survey Steamer ‘Blake’, Lieutenant-Commander C.D.Sigsbee, U.S.N.,
and Commander J.R.Bartlett, U.S.N., Commanding. XV. Preliminary report on the
Mollusca. Bulletin of the Museum of Comparative Zoology Harvard, 9: 33-144.

Dall, W.H. 1886. Reports on the results of dredging, under the supervision of Alexan-
der Agassiz, in the Gulf of Mexico (1877-78) and in the Caribbean Sea (1879-80),
by the U.S. Coast Survey Steamer ‘Blake’, Lieut.-Commander C.D.Sigsbee, U.S.N.,
and Commander J.R.Bartlett, U.S.N., Commanding. XXIX. Report on the Mol-
lusca,—Part I. Brachiopoda and Pelecypoda. Bulletin of the Museum of Comparative
Zoology Harvard, 12: 171-318.

Dall, W.H. 1889. A preliminary catalogue of the shell-bearing marine mollusks and
brachiopods of the southeastern coast of the United States, with illustrations of many
species. Bulletin of the United States National Museum, No.37: 1-221.

Dall, W.H. 1890. Scientific results of explorations of the U.S. Fish Commission
Steamer Albatross. No. VII.— Preliminary report on the collection of Mollusca and
Brachiopoda obtained in 1887-88. Proceedings of the U.S. National Museum,
No.773: 219-361.

Edwards, R.R.C., Steele, J.-H. and Trevallion, A. 1970. The ecology of O-group
Plaice and Common Dabs in Loch Ewe, III. Prey-predator experiments with Plaice.
Journal of Experimental Marine Biology and Ecology, 4: 156-175.

James, B.M. 1972. Systematics and biology of the deep-water Palaeotaxodonta
(Mollusca: Bivalvia) from the Gulf of Mexico. Ph.D. Thesis, Texas A & M University.

Jeffreys, J.G. 1876. New and peculiar Mollusca of the Pecten, Mytilus and Arca
procured in the ‘Valorous’ Expedition. Annals and Magazine of Natural History, ser.
4, 18: 424-436.

Jeffreys, J.G. 1879. On the Mollusca procured during the ‘Lightening’ and ‘Porcupine’
Expeditions, 1868-70. (Part Il). Proceedings of the Zoological Society. of London,
(1879): 533-588.

Knudsen, J. 1970. The systematics and biology of abyssal and hadal Bivalvia.
Galathea Report, 11; 7-241.

Laghi, G.F. 1986. Nucula pusio Philippi, 1844 (Paleotaxodonta, Bivalvia): studio
critico e proposte. Atti e Memorie della Accademia Nazionale di Scienze, Lettere e
Arti di Modena. Ser.VIl, 1 (1983-84): 155-195.

132

Locard, A. 1891. Les coquilles marines des cotes de France. Annales de la Société
Linnéene de Lyon, NS 39: 1-361.

Locard, A. 1898. Expeditions du Travailleur et du Talisman. Mollusques Testacés. Il.
Paris.

Prashad, B. 1932. The Lamellibranchia of the Siboga Expedition. Systematic Part II,
Pelecypoda. Siboga Expedition, 53e: 1-353.

Nijssen-Meyer, J. 1972. Propeleda platessa (Dall, 1890), a nut clam new for the coastal
waters of Surinam (Pelecypoda, Nuculanidae). Zoologische Mededelingen, Leiden,
47: 449-456.

Prashad, B. 1936. The Lamellibranchia of the Siboga Expedition. Systematic Part II
Pelecypoda. Siboga Expeditie, 53¢, 1-353.

Purchon, R.D. 1956. The stomach in the Protobranchia and Septibranchia
(Lamellibranchia). Proceedings of the Zoological Society of London. 127, 5\1—
525.

Rhind, P.M. and Allen, J.A. 1992. Studies on the deep-sea Protobranchia (Bivalvia):
the family Nuculidae. Bulletin of the British Museum of Natural History (Zoology),
58: 61-93.

Rice, W.H. and Kornicker, L.S. 1965. Mollusks from the deeper waters of the
northwestern Campeche Bank, Mexico. Publications of the Institute of Marine
Science of the University of Texas, 10: 108-139 and 172.

Sanders, H.L. and Allen, J.A. 1973. Studies on deep-sea Protobranchia (Bivalvia);
prologue and the Pristiglomidae. Bulletin of the Museum of Comparative Zoology
Harvard, 145: 237-261.

Sanders, H.L. and Allen, J.A. 1977. Studies on the deep-sea Protobranchia (Bivalvia);
the family Tindariidae and the genus Pseudotindaria. Bulletin of the Museum of

J.A. ALLEN AND H.L. SANDERS

Comparative Zoology Harvard. 148: 23-59.

Sanders, H.L. and Allen, J.A. 1985. Studies on deep-sea Protobranchia (Bivalvia); the
family Malletiidae. Bulletin of the British Museum of Natural History (Zoology), 49:
195-238.

Seguenza, G. 1877. Nuculidi terziari rinvenute nelle provincie meridionale d'Italia.
Atti dell’ Accademia del Lincei Memorie, ser.3, 1:1163-1190.

Smith, S. 1888. Lists of dredging stations in North American waters from 1867 to 1887.
Government Printing Office, Washington.

Taylor, A.C., Davenport, J. and Allen, J.-A. 1995. Anoxic survival, oxygen consump-
tion and haemocyanin characteristics in the protobranch bivalve Nucula sulcata
Bronn. Comparative Biochemistry and Physiology, 112A: 333-338.

Theile, J. and Jaeckel, S. 1931. Muscheln der Deutschen Tiefsee-Expedition. Deutsche
Tiefsee-Expedition, 21: 1-267.

Verrill, A.E. 1882. Catalogue of marine Mollusca added to the fauna of the New
England region, during the past ten years. Transactions of the Connecticut Academy
of Arts and Science, 5: 447-587.

Verrill, AE. 1884. Second catalogue of Mollusca recently added to the fauna of the
New England coast and the adjacent parts of the Atlantic, consisting mostly of deep
sea species with notes on oters previously recorded. Transactions of the Connecticut
Academy of Arts and Science, 6: 139-294.

Warén, A. 1989. Taxonomic comments on some protobranch bivalves from the
northestern Atlantic. Sarsia, 74: 223-259.

Yonge, C.M. 1939. The protobranchiate Mollusca; a functional interpretation of their

structure and evolution. Philosophical Transactions of the Royal Society of London,
B, 230: 79-147.

Bulletin of The Natural History Museum
Zoology Series

Earlier Zoology Bulletins are still in print. The following can be ordered from Intercept (address on inside front cover). Where the complete backlist is not shown,
this may also be obtained from the same address.

Volume 53
No. 1

No. 2

No. 3

No. 4

Volume 54
No. |

No. 2

Volume 55
No. 1

Puellina (Bryozoa: Cheilostomata: Cribrilinidae) from British
and adjacent waters. J. D. D. Bishop & B. G. Househam. 1987.
Pp. 1-63. £17.20

Miscellanea.

Notes on Atlantic and other Asteroidea 5. Echinasteridae. Ailsa
M. Clark.

Observations on the marine nematode genus Spirina Gerlach,
1963 (Desmodoridae: Spiriniinae) with descriptions of two
new species. J. W. Coles.

Caleupodes, a new genus of eupodoid mite (Acari:
Acariformes) showing primary opisthosomal segmentation. A.
S. Baker.

The Barbus perince—Barbus neglectus problem and a review of
certain Nilotic small Barbus species (Teleostei, Cypriniformes,
Cyprinidae). K. E. Banister. 1987. Pp. 65-138. £20.55
The genera of pelmatochromine fishes (Teleostei, Cichlidae). A
phylogenetic review. P. H. Greenwood. 1987. £17.20

Certain Actiniaria (Cnidaria, Anthozoa) from the Red Sea and
tropical Indo-Pacific Ocean. K. W. England. 1987. Pp 205-

DO: £23.95
The cranial muscles and ligaments of macrouroid fishes
(Teleostei: Gadiformes) functional, ecological and
phylogenetic inferences. G. J. Howes. 1988. Pp. 1-62. £16.90

A review of the Macrochelidae (Acari: Mesostigmata) of the
British Isles. K. H. Hyatt & R. M. Emberson. 1988. Pp 63-126.
£17.20

A revision of Haplocaulus Precht, 1935 (Ciliophora:
Peritrichida) and its morphological relatives. A. Warren. 1988.
Pp. 127-152. £8.50

Echinoderms of the Rockall Trough and adjacent areas. 3.
Additional records. R. Harvey, J. D. Gage, D. S. M. Billett, A.
M. Clark, G. L. J. Paterson. 1988. Pp. 153-198. £14.00

A morphological atlas of the avian uropygial gland. D. W.
Johnston. 1988. £16.60

Miscellanea.

A review of the Copepod endoparasites of brittle stars
(Ophiuroida). G. A. Boxshall.

A new genus of tantulocaridan (Crustacea: Tantulocarida)
parasitic on a harpacticoid copepod from Tasmania. G. A.
Boxshall.

Unusual ascothoracid nauplii from the Red Sea. G. A. Boxshall
& R. Bottger-Schnack.

New nicothoid copepods (Copepoda: Siphonostomatoida) from
an amphipod and from deep sea isopods. G. A. Boxshall & K.
Harrison.

A new genus of Lichomolgidae (Copepoda:
Poecilostomatoida) associated with a phoronid in Hong Kong.
G. A. Boxshall & A. G. Humes. 1988. £9.00

Miscellanea.

Structure and taxonomy of the genus Delosina Wiesner, 1931
(Protozoa: Foraminiferida). S. A. Revets.

Morphology and morphogenesis of Parakahliella haideri nov.

Volume 56

No. |

Volume 57

No. |

No. 2

spec. (Ciliophora, Hypotrichida). H. Berger & W. Foissner.
Morphology and biometry of some soil hypotrichs (Protozoa,
Ciliophora) from Europe and Japan. H. Berger & W. Foissner.
Polyclad turbellarians recorded from African waters. S.
Prudhoe, O.B.E.

Ten new taxa of chiropteran myobiids of the genus
Pteracarus (Acarina: Myobiidae). K. Uchikawa.

Anatomy and phylogeny of the cyprinid fish genus
Onychostoma Ginther, 1896. C. Yiyu. 1989.

Pp. 1-121. £30.00

Studies on the Deep Sea Protobranchia: The Subfamily
Ledellinae (Nuculanidae). J. A. Allen & F. J. Hannah.

1989. £38.00

Osteology of the Soay sheep. J. Clutton-Brock, K. Dennis-
Bryan, P. L. Armitage & P. A. Jewell.

A new marine species of Euplotes (Ciliophora, Hypotrichida)
from Antarctica. A. Valbonesi & P. Luporini.

Revision of the genus Eizalia Gerlach, 1957 (Nematoda:
Xyalidae) including three new species from an oil producing
zone in the Gulf of Mexico, with a discussion of the sibling
species problem. D. Castillo-Fernandez & P. J. D.
Lambshead.

Records of Neba!ia (Crustacea: Lepostraca) from the
Southern Hemisphere a critical review. Erik Dahl.

1990. £31.00

Tinogullmia riemanni sp. nov. (Allogromiina: Foraminiferida),
a new species associated with organic detritus in the deep-sea.
A. J. Gooday.

Larval and post-larval development of Anapagurus
chiroacanthus (Lilljeborg, 1855) Anomura: Paguroidea:
Paguridae. R. W. Ingle.

Redescription of Martialia hyadesi Rochebrune and Mabille,
1889 (Mollusca: Cephalopoda) from the Southern Ocean. P.
G. Rodhouse & J. Yeatman.

The phylogenetic relationships of salmonoid fishes. C. P. J.
Sanford.

A review of the Bathygadidae (Teleostei: Gadiformes). G. J.
Howes & O. A. Crimmen. 1990. £36.00

Morphology and biometry of twelve soil testate amoebae
(Protozoa, Rhizopoda) from Australia, Africa and Austria. G.
Liiftenegger & W. Foissner

A revision of Cothurnia (Ciliophora: Peritrichida) and its
morphological relatives. A. Warren & J. Paynter

Indian Ocean echinoderms collected during the Sinbad
Voyage (1980-81): 2. Asteroidea. L. M. Marsh & A. R. G.
Price

The identity and taxonomic status of Tilapia arnoldi Bilchrist
and Thompson, 1917 (Teleostei, Cichlidae). P. H. Greenwood
Anatomy, phylogeny and txonomy of the gadoid fish genus
Macruronus Giinther, 1873, with a revised hypothesis of
gadoid phylogeny. G. J. Howes £38.50

The pharyngobranchial organ of mugilid fishes; its structure,
variability, ontogeny, possible function and taxonomic utility.
I. J. Harrison & G. J. Howes

Cranial anatomy and phylogeny of the South-East Asian
catfish genus Belodontichthys. G. J. Howes & A. Fumihito

Volume 58

No. 1

No. 2

Volume 59

No. 1

A collection of seasnakes from Thailand with new records of
Hydrophis belcheri (Gray). C. J. McCarthy & D. A. Warrell
The copepod inhabitants of sponges and algae from Hong
Kong. S. Malt

The freshwater cyclopoid of Nigeria, with an illustrated key
to all species. G. A. Boxshall & E. I. Braide

A new species of Ferdina (Echinodermata: Asteroidea) from
the Sultanate of Oman with discussion of the relationships of
the genus within the family Ophidiasteridae. L. M. Marsh & A.
C. Campbell £38.50

The morphology and phylogeny of the Cerastinae (Pulmonata:
Pupilloidea). P. B. Mordan

A redescription of the uniquely polychromatic African cichlid
fish Tilapia guinasana Trewavas, 1936. P. H. Greenwood

A revision and redescription of the monotypic cichlid genus
Pharyngochromis (Teleostei, Labroidei). P. H. Greenwood
Description of a new species of Microgale (Insectivora:
Tenrecidae) from eastern Madagascar. P. D. Jenkins

Studies on the deep-sea Protobranchia (Bivalvia): the family
Nuculidae. P. M. Rhind and J. A. Allen £40.30

Notes on the anatomy and classification of ophidiiform fishes
with particular reference to the abyssal genus Acanthonus
Giinther, 1878. G. J. Howes

Morphology and morphogenesis of the soil ciliate Bakuella
edaphoni nov. spec. and revision of the genus Bakuella
Agamaliev & Alekperov, 1976 (Ciliophora, Hypotrichida). W.
Song, N. Wilbert and H. Berger

A new genus and species of freshwater crab from Cameroon,
West Africa (Crustacea, Brachyura, Potamoidea,
Potamonautidae). N. Cumberlidge and P. F. Clark

On the discovery of the male of Mormonilla Giesbrecht, 1891
(Copepoda: Mormonilloida) R. Huys, G. A. Boxshall and R.
Bottger-Schnack £40.30

A new snake from St Lucia, West Indies. G. Underwood
Anatomy of the Melanonidae (Teleostei: Gadiformes), with
comments on its phylogenetic relationships. G. J. Howes

A review of the serranochromine cichlid fish genera
Pharyngochromis, Sargochromis, Serranochromis and Chetia
(Teleostei: Labroidei). P. H. Greenwood

A revision of Danielssenia Boeck and Psammis Sars with the
establishment of two new genera Archisenia and Bathypsammis
(Harpacticoida: Paranannopidae). R. Huys and J. M. Gee.

A new species of Syrticola Willems & Claeys, 1982 (Cope-
poda: Harpacticoida) from Japan with notes on the type
species. R. Huys and S. Ohtsuka

Erratum £40.30

The status of the Persian Gulf sea snake Hydrophis lapemoides
(Gray, 1849) (Serpentes, Hydrophiidae). A. Redsted
Rasmussen.

Volume 60
No. |

No. 2

Volume 61
No. |

No. 2

Volume 62
No. |

Taxonomic revision of some Recent agglutinated foraminifera
from the Malay Archipelago, in the Millett Collection, The
Natural History Museum, London. P. Bronnimann and J. E.
Whittaker.

Foregut anatomy, feeding mechanisms, relationships and
classification of the Conoidea (=Toxoglossa)(Gastropoda). J.
D. Taylor, Y. I. Kantor and A.V. Sysoev. 1993. Pp. 97—???.
£40.30

A new subfamily and genus in Achatinidae (Pulmonata:
Sigmurethra). A. R. Mead.

On Recent species of Spiraserpula Regenhardt, 1961, a
serpulid polychaete genus hitherto known only from Creta-
ceous and Tertiary fossils. T. Gottfried Pillai and H.A. Ten
Hove. 1994. Pp. 1-104.

Phylogenetic relationships between arietellid genera (Cope-
poda: Calanoida), with the establishment of three new genera.

S. Ohtsuka, G. A. Boxshall and H. S. J. Roe. 1994. Pp. 105—
tea

A revised familial classification for certain cirrhitoid genera
(Teleostei, Percoidei Cirrhitoidea), with comments on the
group’s monophyly and taxonomic ranking. P.H. Greenwood.
Studies on the deep-sea Protobranchia (Bivalvia); the
Subfamily Yoldiellinae. J.A. Allen, H.L. Sanders and F.
Hannah. 1995. Pp. 1-90.

Primary studies on a mandibulohyoid ‘ligament’ and other
intrabucal connective tissue linkages in cirrhitid, latrid and
cheilodactylid fishes (Perciformes: Cirrhitoidei). P.H.
Greenwood

A new species of Crocidura (Insectivora: Soricidae) recovered
from owl pellets in Thailand. P.D. Jenkins and A.L. Smith
Redescription of Sudanonautes Floweri (De Man, 1901)
(Brachyura: Potamoidea: Potamonautidae) from Nigeria and
Central Africa. N. Cumberlidge

Association of epaxial musculature with dorsal-fin
pterygiophores in acanthomorph fishes, and its phylogenetic
significance. R.D. Mooi and A.C. Gill. 1995. Pp. 91-138.
£40.30

Deep-sea conolidean gastropods collected by the John Murray
Expedfition, 1933-34. A.V. Sysoev.

Reassessment of ‘Calcinus’ astathes Stebbing 1924 (Crustacea:
Anomura: Paguridea: Diogenidae). P.A. McLaughlin.

On a new species of Ophidiaster (Echinodermata: Asterpodea)
from southern China. Y. Liao and A.M. Clark.

The life cycle of Paracyclops fimbriatus (Fischer, 1853)
(Copepoda, Cyclopoida). S. Karaytug and G.A. Boxshall. Pp
1-70. £40.30

£40.30

£40.30

£40.30

e

GUIDE FOR AUTHOR'S

Policy. The Bulletin of the British Museum (Natural History)
Zoology, was established specifically to accommodate manu-
scripts relevant to the Collections in the Department of Zoology. It
provides an outlet for the publication of taxonomic papers which,
because of their length, prove difficult to publish elsewhere. Prefer-
ence is given to original contributions in English whose contents are
based on the Collections, or the description of specimens which are
being donated to enhance them. Acceptance of manuscripts is at the
discretion of the Editor, on the understanding that they have not been
submitted or published elsewhere and become the copyright of the
Trustees of the Natural History Museum. All submissions will be
reviewed by at least two referees.

Manuscripts. ‘Initially three clear, complete copies should be
submitted in the style and format of the Bulletin. The text must be
typed double-spaced throughout, including references, tables and
legends to figures, on one side of A4 paper with 2.5 cm margins. All
pages should be numbered consecutively, beginning with the title
page as p. 1. SI units should be used where appropriate.

Whenever possible a copy of the text, once the paper has been
accepted, should also be provided on floppy disc (see below). Discs
should only be sent after final acceptance, as papers generally need
revision after refereeing. If it is impossible to provide an appropriate
disc please ensure that the final typescript is clearly printed.

Authors are requested to ensure that their manuscripts are in final
format, because corrections at proof stage may be charged to the
author. Additions at proof stage will not normally be allowed. Page
proofs only will be sent.

Word-processor discs. Please follow these instructions.

1. Ensure that the disc you send contains only the final version
of the paper and is identical to the typescript.

2. Label the disc with the author’s name, title of the paper and
the word-processor programme used. Indicate whether IBM or
Apple Mac (IBM preferred).

3. Supply the file in the word-processor format; if there is a
facility to save in ASCII please submit the file in ASCII as well.

4. Specify any unusual non-keyboard characters on the front
page of the hard copy.

5. Do not right-justify the text.

6. Do not set a left-hand margin.

7. Make sure you distinguish numerals from letters, e.g. zero
(0) from O; one (1) from 1 (el) and I.

8. Distinguish hyphen, en rule (longer than a hyphen, used
without a space at each end to signify ‘and’ or ‘to’, e.g. the Harrison—
Nelson technique, 91-95%, and increasingly used with a space at
each end parenthetically), and em rule (longer than an en rule, used
with a space at each end parenthetically) by: hyphen, two hyphens
and three hyphens, respectively. Be consistent with rule used paren-
thetically.

9. Use two carriage returns to indicate beginnings of para-
graphs.

10. Beconsistent with the presentation of each grade of heading
(see Text below).

Title. The title page should be arranged with the full title; name(s)
of author(s) without academic titles; institutional address(es); sug-
gested running title; address for correspondence.

Synopsis. Each paper should have an abstract not exceeding 200
words. This should summarise the main results and conclusions of

the study, together with such other information to make it suitable
for publication in abstracting journals without change. References
must not be included in the abstract.

Text. All papers should have an Introduction, Acknowledgements
(where applicable) and References; Materials and Methods should
be included unless inappropriate. Other major headings are left to
the author’s discretion and the requirements of the paper, subject to
the Editors’ approval. Three levels of text headings and sub-headings
should be followed. All should be ranged left and be in upper and
lower case. Supra-generic systematic headings only should be in
capitals; generic and specific names are to be in italics, underlined.
Authorities for species names should be cited only in the first
instance. Footnotes should be avoided if at all possible.

References. References should be listed alphabetically. Authori-
ties for species names should not be included under References,
unless clarification is relevant. The author’s name, in bold and lower
case except for the initial letter, should immediately be followed by
the date after a single space. Where an author is listed more than
once, the second and subsequent entries should be denoted by a long
dash. These entries should be in date order. Joint authorship papers
follow the entries for the first author and an ‘&’ should be used
instead of ‘and’ to connect joint authors. Journal titles should be
entered in full. Examples: (i) Journals: England, K.W. 1987. Certain
Actinaria (Cnidaria, Anthozoa) from the Red Sea and tropical Indo-
Pacific Ocean. Bulletin of the British Museum (Natural History),
Zoology 53: 206-292. (ii) Books: Jeon, K.W. 1973. The Biology of
Amoeba. 628 p. Academic Press, New York & London. (iii) Articles
from books: Hartman, W.D. 1981. Form and distribution of silica in
sponges. pp. 453-493. In: Simpson, T.L. & Volcani, B.E. (eds)
Silicon and Siliceous Structures in Biological Systems. Springer-
Verlag, New York.

Tables. Each table should be typed on a separate sheet designed to
extend across a single or double column width of a Journal page. It
should have a brief specific title, be self-explanatory and be supple-
mentary to the text. Limited space in the Journal means that only
modest listing of primary data may be accepted. Lengthy material,
such as non-essential locality lists, tables of measurements or
details of mathematical derivations should be deposited in the
Biological Data Collection of the Department of Library Services,
The Natural History Museum, and reference should be made to
them in the text.

Illustrations. Figures should be designed to go across single
(84 mm wide) or double (174mm wide) column width of the
Journal page, type area 235 x 174 mm. Drawings should be in black
on white stiff card or tracing film with a line weight and lettering
suitable for the same: reduction throughout, either 50%, 30% or
25%. After reduction the smallest lettering should be not less than
10 pt(3 mm).All photographs should be prepared to the final size of
reproduction, mounted upon stiff card and labelled with press-on
lettering. Components of figure-plates should be abutted. All fig-
ures should be numbered consecutively as a single series. Legends,
brief and precise, must indicate scale and explain symbols and
letters.

Reprints. 25 reprints will be provided free of charge per paper.
Orders for additional reprints can be submitted to the publisher on
the form provided with the proofs. Later orders cannot be accepted.

CONTENTS

71. Indian Ocean echinoderms collected during the Sindbad Voyage (1980-81): 3. Ophiuroidea
and Echinoidea
Andrew R.G. Price and Francis W.E. Rowe

83 Rare cyclopoid copepods (Crustacea) from Mediterranean littoral caves
D. Jaume and G.A. Boxshall

101 Studies on the deep-sea Protobranchia (Bivalvia): the family Neilonellidae and the family

Nuculanidae.
JA. Allen and H.L. Sanders

Bulletin of The Natural History Museum i

ZOOLOGY SERIES
Vol. 62, No. 2, November 1996