174 Transactions. — Zooloyy. 



Art. XIII. — On the Protective Resemblances of the Araneidea in New Zealand. 



By A. T. Uequhart. 

 [Read before the Auckland Institute, 26th June, 1882.] 

 Although a large amount of valuable work has been clone by naturalists in 

 New Zealand, the Araneidea, as far as I am aware, have been comparatively 

 neglected ; yet it is an order that will repay careful research. The protec- 

 tive resemblances are of considerable interest, and the conformity of tints, 

 which exists between most forms of animal life and their habitations, 

 obtains in the spider fauna. Although more or less conspicuous on webs, 

 when resting beneath boughs, foliage, amongst fragments of rock or loose 

 earth, there is a general similarity of colouration between them and their 

 surroundings, which not only affords them means of concealment, but 

 assistance in entrapping their prey. A large proportion of our spiders are 

 dull-coloured, many possess imitative tints. "What the transforming causes 

 are which produce animal colouration cannot be actually determined, as 

 there are apparent difficulties, especially in some individual cases. Owing 

 to the pugnacity of the Araneidea, systematic experiments are attended 

 with considerable difficulties. 



As most spiders, when it is advantageous to them, habitually select, as 

 their resting-places, leaves, parts of leaves, patches of bark, etc., whose 

 colouring corresponds with their own, there can be no doubt that their 

 protective colouring is largely influenced by the survival — through escaping 

 the observation of their enemies — of those spiders to whom their own par- 

 ticular colouration is most attractive. They appear to possess the instinct, 

 the inherited habit, of discerning resting-places that will render them the 

 least conspicuous ; for often the concealment, derived from the spot selected, 

 merely consists of the more or less perfect assimilation of form and colour 

 between the spider and its immediate environment. Some species that 

 may be considered nocturnal — as it would be of no advantage to them — do 

 not possess this habit, but conceal themselves beneath closely-spun webs, in 

 crevices, etc. ; their usually black, or dark-grey colouring rendering them 

 inconspicuous when they sally forth at night in search of prey. 



The most perfect examples of protective colouring met with in the 

 Orbitelaria have been amongst the Epeira that frequent dead shrubs — as 

 might have been inferred from their greater need of concealment, owing to 

 the absence of foliage. My attention was more especially drawn to them in 

 1874, when I carefully searched through upwards of forty acres of manuka 

 (Leptospermum) — burnt two years previously. I found, with very few excep- 

 tions, that their colours corresponded with the charred shrubs ; being of 

 various shades, ashy-grey, marked with black. Some spiders are a pale ash- 



