Timms: A revision of Limnadopsis clam shrimps 
53 
Fortescue River, Mulga Downs Station, near Bunji Well, 
muddy pool, 22°10'S 118°26’E, 3.vii.l970, M.H. Shepherd, 
WAMC39325; Barrow Is., 20°52'S 115°24'E, 18.iv.1976, C. 
Butler, WAM C39326; near Leinster, mine site, waterhole in 
dry creek bed, 20.iii.2001, G. Walker, WAM C28201; 120 
km NNE of Broome, “Bungnaduk”, 8.ii. 1989, J. Martin, 
WAM C39327; 1 ?, NE of Carnarvon, Mardathuna Station, 
Bulgra pool, 24°24’S 114°33’E, 21.iii.1995, S.A. Halse, 
WAM C39328; 1 S , 7 $, NE of Carnarvon, Cooralya Station, 
Bluebush Bore Swamp, 24°28’S 114°18’E, 21.iii.1995, S.A. 
Halse, WAM C39329; 3 9 , near Laverton, 22 km northwest 
on highway, samphire swamp, 28°36'S 122°13'E, 17.ii.2003, 
B. Datson, WAM C39330. 
Distribution. Australia-wide (but not recorded from Victoria 
or Tasmania), generally in the arid and semiarid inland. 
Comments. This large distinctive species was first described 
by Baird in 1860 as Estheria birchii on the basis of a female 
collected in floodplain lagoons of the Namoi (misspelt 
Wamoi) River, NSW. The description is poor, but there is no 
doubt that what is today known as L. birchii was the subject. 
In 1896 Spencer and Hall published a detailed description 
of a species from central Australia that they placed in a new 
genus and called Limnadopsis squirei. Sayce (1903) realized 
that Baird’s E. birchii and the new L. squirei were synony¬ 
mous. Since then, many authors (see synonymy list above) 
have mentioned the species, perhaps with new distribution 
records, but without adding to its known features. 
Spencer & Hall’s (1896) description is almost adequate, 
but it lacks a description of the thoracopods. The thoracopods 
of basic structure noted for spinicaudatans (McLaughlin, 
1980; Alonso, 1996; Ferreri & Grygier, 2003). The male third 
thoracopod (Fig. 4A) with five endites on medial surface, 
each with differing numbers of setae (1st with c. 20; 2nd with 
c. 40; 3rd with c. 30, 4th with c. 30; 5th with c. 25). These 
setae not evenly distributed but sparse in middle region of 
the endite and crowded at proximal end, more so on the 
4th and 5th endites than on others. Fifth endite elongated, 
and similar in shape to finger-like endopod. Fifth endite 
bearing a one-segmented palp slightly longer than endite. 
Exopod bipolar with finger-like extensions distally (termed 
a flabellum by McLaughlin, 1980) and proximally. Endopod 
clothed with c. 60 setae and exopod with more than 100 setae. 
All setae two-segmented and differing slightly as to degree 
of feathering—exopod and endopod setae fully feathered, 
most endite setae with proximal segment sparsely feathered 
and distal segment densely feathered, and setae of the 5th 
endite naked. Oval-shaped, naked epipodite lying between 
proximal lobe of exopod and the main axis carrying endites. 
Other thoracopods essentially similar to third, but without 
palp on 5th endite and with slightly differing proportions of 
parts, particularly of epipodite. Female thoracopods similar 
to those of males but without palp on 5th endite, and ninth 
and tenth pairs with projections of exopod on which eggs 
carried. 
Eggs (Fig. 5A,B) round, about 172 pm in diameter (range 
162-186 pm, n = 10), with parallel groups of ridges and 
deep clefts arranged around surface. No major differences 
in this respect between eastern and western populations (Fig. 
5A,B) studied. 
Variability. Limnadopsis birchii is more variable than 
indicated by Spencer & Hall (1896). The carapace shape 
(Figs. 2A, 3A) is broadly oval, but usually with a distinct 
anterodorsal angle of about 120°, and a convex dorsal 
margin that is slightly depressed anterior of the umbo. The 
dorsal margin, posterior of the embryonic valve, bears many 
asymmetrical carinae (= “backwardly directed serrations” 
of Spencer & Hall 1896), the posterior edges of which are 
Fig. 4. Third thoracopods of males of (A) L. birchii ; ( B ) L. tatei’, (C) L. parvispinus; and (D) L. paradoxa n.sp. A few of the numerous 
setae (see text), and details of the major types of setae are shown only for L. birchii. Scale bars 1 mm. 
