60 Mr. R. I. Pocock on the Australian 



(1) a single, movable, claw-like spur on the articular mem- 

 brane at the base of the foot ; (2) a pentagonal sternum ; (3) a 

 pair of lateral eyes on each side of the carapace ; (4) a median 

 keel on the lower surface of the first four caudal segments. 

 The pentagonal sternum and the single pedal spur are also 

 found in the genus Hormurus ; but in the latter there are 

 three lateral eyes on each side of the carapace and a pair of 

 crests or keels on the lower side of the first four caudal 

 segments. 



These two genera are the only representatives of the 

 Scorpionidae that occur in Australia. Hormurus, however, is 

 certainly a later immigrant than Urodacus, for it is only met 

 with in the north-eastern parts of the country, and belongs 

 essentially to the Indo- and Austro- Malayan area. 



Urodacus, on the contrary, has not, so far as I am aware, been 

 recorded from Queensland at all, though it not improbably 

 spreads into the southern parts of that province. Up to the 

 present time, including those described as new in this paper, 

 twelve species have been established, with ten of which I 

 have the good fortune to be acquainted from an actual exam- 

 ination of specimens. The others, described by Dr. Thorell 

 as Ioctonus inanicatus and /. orthurus, were referred by that 

 author to a different genus, owing, according to Kraepelin, to 

 an error of observation with respect to the number of crests 

 on the lower side of the tail. Again, according to Kraepelin, 

 inanicatus is specifically identical with the type of the genus, 

 U.novce-hollandice, which occurs in the neighbourhood of Perth. 

 The identity of /. orthurus still remains in doubt. Lastly, 

 the form that I described as U. Keyserlingii proves upon the 

 examination of fresh material to be identical with a species 

 previously established as U. abruptus ; so that the total 

 number of species now to be reckoned with amounts to ten of 

 which the characters are known, and one (orthurus) of which 

 the characters are doubtful. 



A glance at the species and localities mentioned below 

 shows that two species have been described from Arnhem Land 

 in North Australia; two from the central parts of West Aus- 

 tralia ; two from the south-western corner in the neighbourhood 

 of Perth ; one from South Australia ; and from Victoria and 

 New South Wales one species, which spreads as far westward 

 as Adelaide. It is noticeable that, with the exception of the 

 New South Wales species and the two here recorded from 

 the neighbourhood of the Murchison Goldrields, all the species 

 have been met with at various points on the coast of Aus- 

 tralia. It cannot be doubted therefore that at the present 



