I'KDAI. XciSI-: l.\ 'IkAI'-DOoK SI'IDIIKS. :^4 I 



each other, she raised ujjwards on her abdonieti and liindle^s, 

 and he approachinjy lier l)eneath, at hrst with incessant i)attinfi, 

 but eventually his leg movements ceased. The movements of 

 the male palps I was unable to follow. 



The ordinary ambulatory movements of the male of this 

 species are fairl\- slow; the body is carried close to the .g^round, 

 the palps down, and the le.s^s wide-spreadint^. feelint^ his way at 

 everv stc]). 



As 1 hap]>ened to have the male of another species of Acan- 

 ihodon I allowed him to walk near to and to touch two adult 

 females of kcntanicus: he merely shewed ordinarv symptoms of 

 alarm without any indication of courting attitude. 



Experiments with the males of Stasimopus and nesting 

 females were unsuccessful. The male in such case took up the 

 courting attitude previously described for this species and 

 scratched on and near to the trapdoor, but there was no definite 

 tai)ping. and the female did not respond in any way. No doubt 

 mating will nominally take place at night, when both sexes of 

 Stasiuiopus are comtxiratively active. 



Rkferexcf.s. 



1. G. and E. Peckham. " On the Mental I'owers of Si)iders," 



J. Morph. (Boston, U.S.A.), 1 (18S7). 



2. N. E. ]\rindoo, " The Lyriform Organs and Tactile Hairs of 



Araneads." Proc. Achd. Nat. Sci. Philadelphia (igiO, 



375-418. 



" The Olfactory Sense of Insects. Smithsonian mis- 

 cellaneous collections, publication 2315 (TCJ14). 



" The Sense Organs on the Mouth Parts of the Honey 

 Bee."- Smithsonian miscellaneous collections, juiblication 

 2381 ( iyi6). 



3. T. H. Montgomery, " Studies of the Habits of S]>iders, par- 



ticularly those of the Mating Period."' Proc. Acad. Ahit. 

 Sci. Philadelphia ( 1903). 59-149. 



Clouds on Mars. — A recent issue of Nature contains a 

 summary of a report on the planet Mars by Prof. W. Jl. Picker- 

 ing, in the course of which it is stated that during its. last op])osi- 

 tion the planet was scarcely ever seen without clouds, although 

 a few years ago it was claimed by some observers that clouds are 

 never or rarely seen on Mars. Prof. Pickering says that the 

 clouds always lie over the so-called desert regions of the planet, 

 ap])arently being precijjitated as soon as the fertile regions are 

 reached. 



