38 
P.M. O’Loughlin, S. Barmos & D. VandenSpiegel 
Methods 
For scanning electron microscope (SEM) observations by 
Didier VandenSpiegel ossicles were cleared of associated soft 
tissue in commercial bleach, air-dried, mounted on aluminium 
stubs, and coated with gold. Observations were made using a 
JEOL JSM-6480LV SEM. Measurements were made with 
Smile view software. Photos of preserved specimens by Shari 
Barmos were taken with a Nikon D70 DSLR camera, using a 
Nikon micro 60 mm lens. 
Abbreviations 
AM Australian Museum (with registration prefix J). 
MRG Marine Research Group of the Field Naturalists Club of 
Victoria. 
NMV Museum Victoria (with registration prefix F). 
NIWA New Zealand Institute of Water and Atmospheric 
Research. 
SAM South Australian Museum (with registration prefix K). 
WAM Western Australian Museum (with registration prefix Z). 
Numbers in brackets after registrations refer to the number 
of specimens in a registered lot. 
Spelling correction 
Some authors have misspelled the species name ransonnetii, 
and the correct spelling only is used throughout our work. 
Key to the Australian and New Zealand species of 
Paracaudina Heding 
1. Ossicles in body wall small irregular rods only. 
Paracaudina bacillis O’Loughlin and Barmos sp. nov. 
(southern Australia) 
— Ossicles in body wall include small buttons or perforated 
plates or thick cups.2 
2. Ossicles in mid-body predominantly small rods and loops, 
and in caudal end predominantly spinous perforated 
plates. Paracaudina ambigua O’Loughlin and Barmos 
sp. nov. (central Western Australia) 
— Ossicles similar in mid-body and caudally.3 
3. Ossicles in body wall predominantly octagonal plates 
with central perforation over which there is a bridging box 
on the basal side and cross on the outer side.4 
— Ossicles in body wall rarely octagonal plates with box and 
cross bridges, or such ossicles completely absent.6 
4. Octagonal plates predominantly with marginal bluntly 
pointed projections and knobs; perforations not 
significantly smaller in collective area than the surface 
area of the plate; body with long thin tail. Paracaudina 
chilensis (Muller, 1850) (circum-Pacific, north-western 
Australia) 
— Octagonal plates predominantly with rounded margin, 
margin lacking bluntly pointed projections and knobs ... 5 
5. Ossicles predominantly thick and button-like, perforations 
significantly smaller in collective area than the plate 
surface area; body with long thin tail. Paracaudina 
coriacea (Hutton, 1872) (New Zealand) 
— Ossicles predominantly thin-walled and open mesh-like, 
perforations not significantly smaller in collective area 
than the plate surface area; body with short thin tail. 
Paracaudina keablei O’Loughlin and Barmos sp. nov. 
(north-eastern Australia) 
6. Ossicles in body wall predominantly thick-walled with 4 
perforations.7 
— Ossicles in body wall include irregular plates and buttons 
with irregular perforations, with marginal and surface 
knobs and pointed projections variably present; plates 
with up to 12 perforations.8 
7. Ossicles in body wall predominantly thick, shallow 
concave crossed cups Paracaudina luticola Hickman, 
1962 (southern Australia) 
— Ossicles in body wall predominantly thick, knobbed and 
irregularly oval flat plates. Paracaudina tetrapora (H. 
L. Clark, 1914) (southern Australia) 
8. Ossicles in body wall predominantly buttons with smooth 
rounded lateral margin, short thick blunt surface spines, 
frequently with central perforation bridged by a tripod of 
rods ... Paracaudina tripoda O’Loughlin and Barmos, sp. 
nov. (north-eastern Australia) 
— Ossicles in body wall plates, most with lateral and surface 
rounded marginal spines and knobs.9 
9. Deeper mid-body wall with irregular rods, less than 50 
pm long; colour never yellowish-red (rusty). 
Paracaudina australis (Semper, 1868) (north-eastern 
Australia) 
— Deeper mid-body wall lacking irregular rods; larger 
specimens increasingly yellowish-red (rusty) in colour. 
Paracaudina cuprea O’Loughlin and Barmos sp. nov. 
(southern Australia) 
Remarks. The remaining subspecies and species of 
Paracaudina Heding, 1932 that are not included in this key are: 
Paracaudina chilensis obesacauda (H. L. Clark, 1908), a 
central American east Pacific and west Atlantic subspecies, 
retained with subspecific status solely on geographical grounds 
by Pawson et al. 2001; Paracaudina delicata Pawson and Liao, 
1992, from the Gulf of Tonkin, has thin-walled chilensis- like 
ossicles, with box and cross bridging a central perforation, and 
fine digitiform projections around the ossicle margin. 
Order Molpadida Haeckel, 1896 
Diagnosis (emended from Pawson and Liao 1992). Tentacles 
15, digitate; body stout, lacking tube feet, usually with an 
evident tail; anal papillae, tentacle ampullae and respiratory 
trees present; ossicles may include tables, cups, rods, perforated 
plates and modified anchors; phosphatic bodies often present. 
