20 



descent below the surface is merely a protective measure. An arach- 

 nid of these habits would not require the complete and lasting supply 

 of air which is so conspicuous in the appearance of A. aquatica. All 

 that we notice, for instance, when P. piraticus is driven under water 

 is the formation of bubbles entangled by the hairy abdomen, con- 

 stituting a sufficient temporary protection, but no deep and complete 

 atmospheric envelope like that of A. aquatica. 



To return again to this last-named spider, before closing this 

 paper, Mons. Simon suggests that Rossi has fallen into some confu- 

 sion in mentioning three species of Argyroneta {Iri/ineata, palusfris, 

 bicolor) as occurring near Nice, and that he has included in the genus 

 young specimens of Dolomedes and Firata. 



This remark explains to some degree why, in treating of Arg}'ro?ieta, 

 I have added notices of some other spiders. I can only wish that 

 I had been able to add the results of more personal knowledge and 

 observation ; but, while I hope that time and diligence may entitle 

 me, later, to speak with more certainty and precision on the Aratieidce, 

 I can, at present, only bring before you the impressions of a learner 

 in this interesting but complicated branch of biological study. 



