Schizaster compactus from Western Australia 
317 
Figure 1 Schizaster (Schizaster) compactus (Koehler, 1914) from the Dampier Archipelago, Western Australia. WAM 
133-93: A, aboral surface, stereo pair; B, adoral surface; C, lateral view. WAM 132-93, juvenile: D, aboral 
surface; E, adoral surface; F, lateral view. All x2. 
floridiensis Kier and Grant 1965 (see also Chesher 
1966). In Schizaster (s.s.) ambulacrum III is deeper, 
the pore pairs are more numerous (although in 
single rows) and aligned transversely, or nearly so 
(e.g., Mortensen 1951, p.301, figure 140; McNamara 
and Philip 1980a, figure 4D). Species with this 
morphology are known to be able to burrow in 
mud. Thus of the Cuban species of Schizaster 
recognised by Kier (1984), S. camagueyensis, S. 
cubitabellae, S. fernandezi and S. subcylindricus can 
all be assigned to the subgenus Paraster, as all have 
a shallow ambulacrum III with a relatively small 
number (less than 15) of obliquely aligned pore 
pairs, whereas S. bathypetalits, S. delgadoi, S. 
egozcuei, S. gerthi, S. llagunoi, S. munozi, S. 
nuevitasensis, S.formelli, S. rojasi, S. sanctamariae and 
S. santanae, with their greater number of 
transversely orientated pore pairs, can be 
accommodated within the subgenus Schizaster. It is 
worth noting that one of the principle 
characteristics of the type species of Paraster, P. 
gibberulus, is its possession of very obliquely 
arranged pore pairs in ambulacrum III aborally 
(Mortensen 1951, p.220, figure 104b), while in S. 
studeri, the type species of Schizaster, the pore pairs 
are closely spaced, transverse and numerous 
(Mortensen 1951, p.297, figure 136). 
Species of Schizaster in which the pore pairs are 
so crowded in ambulacrum III that they effectively 
form multiple rows (see McNamara and Philip 
1980a, figure 5C), are classified as a third 
subgenus, S. (Ova), as typified by forms such as S. 
(Ova) myoretisis McNamara and Philip 1980a. 
Consequently a morphocline of increasing 
concentration of pore pairs in ambulacrum III 
aborally exists from S. (Paraster), through S. 
(Schizaster) to S. (Ova) (Figure 2). 
Schizaster (Schizaster) compactus (Koehler, 1914) 
Figure 1 
Paraster compactus Koehler, 1914: 180; Mortensen 
1951: 221-223, plate 24, figures 3-8, plate 52, 
figures 1,3; Ghiold 1989:117,140. 
Schizaster (Schizaster) lacunosus (Linnaeus): (pars) 
McNamara and Philip 1980a: 129-131, figure 1. 
Schizaster (Schizaster) compactus (Koehler): 
McNamara and Kendrick 1994: 46. 
Material Examined 
Australia: Western Australia: WAM 1488-75, 
dredged from a depth of 4-5 m outside Norbill 
Bay, Rosemary Island, Dampier Archipelago; 
WAM 132-93 to 135-93, 33 complete and broken 
specimens from a depth of 45 m north of Dampier, 
at 20°19'33.1"S, 116°33'22.11"E. 
