AUSTRALIAN OPILTOXES. 



43 



carapace and bearing on its Riiinniife a sliort dentiform tubercle. 

 Tiie claws of the third and fourth pairs of legs have the side 

 brandies longer than the median claw in both sexes. I have a 

 male and female which I am placing in the genus following 

 (]\[onoxyomm.a), in which this type of claw appears in the male 

 only, the female having the side claws shorter than the median. 



SORENSENELLA PREHENSOR Poc. 



K. I. Pocock, loc. cit. supra. 

 Locality, New Zealand (only). 



SORENSENELLA BICORNIS PoC. 



R. I. Pocock, Ann. & Mag. Nat. Hist. ser. 7, vol. xi. May 

 1903, p. 439. 

 Male and female from Christchurch, N.Z. 



Genus Monoxyomma Poc. 



R. I. Pocock, Ann. & Mag. Nat. Hist. ser. 7, vol. xi. 

 May 1903, p. 444. 



Mr. Pocock formed this genus for those members of the family 

 Trisenonychidre in which the ocular tubercle, rising distinctly 

 behind the anterior margin of the carapace, is protected by a 

 long suberect spine. He also gives as generic characters a pair 

 of long spines on or about the third abdominal segment, and the 

 doi'sal valve or sheath of penis trilabiate. 



The pair of dorsal spines is far from being peculiar to tliis genus. 

 It is present in a median bifurcated form in one case, and wanting 

 in another, among the species which I am compelled to consider 

 as belonging to this genus since they otherwise conform to the 

 type. 



The third character suffers under the disability of being a 

 sexual one ; and it is a matter of considerable difficulty, in the 

 majority of cases, to ascertain whether it appertains to a par- 

 ticular species or not. 



The following synopsis may help to distinguish the species 

 below recorded : — 



a. Dorsal carapace roughly granular all over M. tuherculatum, sp. n. 



b. Dorsal carapace smooth or small granules onb'. 

 a^. A pair of spinous tubercles near rear end of 



carapace M. spinatum Poc. 



h^. No pair of spinous tubercles near rear end of 

 carapace. 



a". A bifurcated spinous tubercle on median 

 line ; no spines on anterior margin ; palpi 

 1^ times as long as body 31. Jiendei, sp. n. 



b'^. No spinous tubercles on carapace ; a pair of 

 short spines, one on each corner of anterior 

 margin; palpi nearly twice as long as body. M. trailli, s,^. n. 



