GoYEN. — On New Zealand Araneas. 255 



^then stops, rubs its palpi just as a fly rubs its fore-legs, ex- 

 'amines the surface of the rock within its view, then again 

 runs briskly for an inch or two, again stops, rubs its palpi, and 

 •' spies out the land ; " and so on till it comes within view of 

 its prey — or what it takes to be such, for it seems to have some 

 difficulty in distinguishing members of its own species from 

 the flies on which it lives. It now advances exactly like a cat 

 approaching a bird, stealing forward at a pace so slow that 

 one can scarcely see it advancing, until within about an inch 

 of its prey, when it springs swiftly upon the unsuspecting fly, 

 and pinions it with its falces and palpi. Within springing- 

 distance its aim is so sure and its bound so swift that the fly 

 has no chance of escape. Having captured its prey it gene- 

 rally carries it to a depression in the rock, and there, if undis- 

 turbed, sucks its juices at leisure. Half the spiders one sees 

 are thus in hiding with a fly in their jaws. Very often the fly 

 is much larger than the spider ; but the latter, if discovered by 

 another spider, makes off with the captured fly with the 

 greatest ease. It will even leap across a crevice an inch or so 

 wide, and if its covetous brother is persistent in his pursuit, to 

 escape him it will spring into space and hang, head downwards, 

 suspended by a strand of web, but never parting with its prey. 

 In every case I observed the pursued was successful in eluding 

 the pursuing spider. 



This little spider is exceedingly interesting as affording, in a 

 class of animals in which it has not, I believe, beeii before 

 observed, a striking example of aggressive mimicry. 



Fam. THERAPHOSOID^. 

 Gen. Aebanitis, Koch. 



Arbanitis huttonii, Cambr. Plate XIX., figs. 2 and 3. 



Femina. — Length of cephalothorax from 4.|^mm. to 6mm., 

 of abdomen from 8^mm. to 10mm. 



Cephalothorax with its appendages brown, the falces being 

 of a very dark colour ; abdomen above of a somewhat paler 

 hue than the cephalothorax, and below of a much lighter hue 

 than above. The dorsal surface is marked with dark more or 

 less continuous bands, running somewhat obliquely from the 

 median line down the sides, and the ventral surface is also 

 marked with dark spots that in some examples form a fairly 

 distinct pattern, consisting of two transverse bands, greatly 

 enlarged in the middle on the basal side, one in line with the 

 posterior pair of pulmonary orifices, and the other about half- 

 way between these and the spinners. It is only in mature 

 examples that these ventral markings are very distinct. 



Cephalothorax elliptical in outline, truncated in front and 



