158 MR. GEOFFREY SMITH OX THE 



The second abdominal segment has two (sometimes three) 

 smaller lateral and two large dorso-lateral spines on each side. 



The next three abdominal segments have two large dorso- 

 lateral spines, and one (sometimes two) small lateral spine on 

 each side. 



The sixth abdominal segment carries tAvo small lateral spines 

 or tubercles on each side. 



The telson has two (sometimes more, a variable number) 

 median spines. 



The number and arrangement of the above spines is sometimes 

 variable and even asj'mmetrical. 



The great chela has two enlarged tubercles in the pincers, both 

 on the biting-edge of carpopodite. The lower external boi'der of 

 the carpopodite has a row^of sharp and large spines continiied right 

 down to the posterior border. The upper internal border has 

 about five marked serrations. The carpopodite is flattened, 

 and does not carry any tubercles on its other surfaces. The meso- 

 podite has three large spines on its inner border and two on its 

 outer. 



The first two walkingdegs are nearly free from spines, but the 

 last two carry long and prominent spines, especially on the last 

 joint but one. 



Colour (as given by McCoy). — The anterior legs, the middle 

 of the back, and the apices of the spines and tubercles rich 

 creamy white or ivory-coloured ; the ground-colour of the other 

 legs, the sides of the carapace, and the abdomen pale Prussian- 

 blue of varying intensity in difierent individuals, or sometimes 

 mottled with dull olive-green. Semicorneous flexible edges 

 of tail-fin brownish. 



Largest specimen obtained measured 10 inches (about 230 

 mm.); the smallest 7 inches. 



Locality of type specimens. — Murray River. 



Local Varieties. 

 From Victoria. 



(a) Bunyip River. One specimen, January 1880, measuring 

 140 mm. It resembles the Murray River form, except that the 

 spines on carapace and branchiostegites tend to iDe replaced 

 by blunter tubercles, also the dorsal spines on abdominal segments. 

 On second abdominal segment there are four latei'al spines on 

 left side, three on the right, thus illustrating the variability and 

 frequent asymmetry of these spines. 



(6) Yarra River. Sevei-al specimens, 190.5. A large specimen 

 (PI. XVII.), measuring 150 mm., has a single spine on each side 

 of first abdominal segment, three lateral spines on second, and 

 the doi'sal spines on abdominal segments clearly marked but 

 reduced. The smaller specimens, about 100 mm. in length, have, 

 in some cases, a single spine on first abdominal segment, in 

 others two ; there is a great reduction of dorsal spines on the 



