1902.] SPIDERS OF THE GENUS DESIS. 105 



sight deep clown amongst the worm-tubes. How they catch theiv 

 food, what their food is, and how they keep the sea from 

 drowning them, are questions I have not yet demonstrated, 

 though I have tried again and again to keep them in my marine 

 aquaria. Shortly after introducing one, I have often found it 

 floating helplessly on the water, apparently half dead, and I have 

 had it lifted out of the water and placed on the rockwork, when it 

 soon became active and ran about very quickly, when it appeared 

 to be just like an ordinary spider." 



The characters of the species of the genus Besis may be 

 tabulated as follows : — 



a. Ej'es of posterior line subequally spaced ; tibia and protarsns 



of posterior legs strongly spined. 



rt^. Eyes of posterior line closer together, the medians about 



two diameters from each other and from the laterals. 



a". The two teeth on the posterior border of the fang-groove 



close together, the distal much larger and closer to the 



proximal than to the base of the fang (according to 



Simon) maxillosa. 



b". The two teeth on the posterior border of the fang-groove 

 wide apart, the distal not larger than the proximal and 

 equidistant from it and from the base of the fang 



(according to Koch) vorax. 



h^. Eyes of posterior line farther apart, the medians about 



three diameters from each other and from the laterals. 



cfi. Teeth on posterior border of fang-groove relatively close 



together, separated only by a space a little exceeding 



the length of the proximal, the two relativelj'- subequal ; 



teeth of anterior row starting nearer base of fang martensi. 



h^. Teeth of posterior border of fang-groove far apart, 

 separated by a space equalling about three times the 

 length of the proximal, the distal tooth much the larger 

 of the tv.'O ; teeth of anterior row starting farther from 

 base of fang marina. 



h. Eyes of anterior and posterior lines very unequally spaced, 

 the distance between the medians and the laterals far 

 greater than that between the medians ; posterior legs weakly 

 spined or unspined. 

 «■*. Posterior legs without spines (according to Cambridge) ... formidahilis. 

 b*. Posterior legs with tibial and protarsal spines. 

 «-\ Distal tooth on anterior margin of fang-groove remote 

 from the base of the fang and close to the rest of the 

 series ; protarsus of 2nd, 3rd, and 4th legs spined only 

 at apex ; no median crest on floor of cavity of vulva, and 

 the lateral processes shorter and projecting inwards more 



at right angles tubicola. 



b='. Distal tooth on anterior margin of fang-groove nearer 

 to base of fang and remote from the rest of the series ; 

 protarsus of 2nd, 3rd, and 4th legs with a pair of 

 spines on the proximal side of the scopula as well as at 

 apex ; vulva with median crest on floor of cavity, and 

 lateral processes pi'ojecting obliquely backwards Tcenyona. 



The discovery that a close specific relationship obtains between 

 the South African and South Australian species is of the highest 

 interest from a geographical standpoint, as favouring the 

 hypothesis of a direct land connection, accompanied by temperate 

 conditions, between these two continents. All the evidence that 



