14S 'My. T. n. Savory on tlie Spider Liplilstius. 



The groupin<T of spiders' ojes is a very valuable feature in 

 taxonomy. The course of evolution seems, roughly speaking, 

 to indicate a general wandering of the eyes away from their 

 close proximity around and upon an ocular tubercle, so that 

 they spread over a larger area of the cephalothorax. The 

 retention aiid elaboration of the ocular tubercle in the Liny- 

 phiidre is a secondary specialization, and the reduction of the 

 number of eyes to six, four, two, or none in the suborder 

 Tubitellarige would seem to bo a degenerate rather than a 

 primitive condition. The eyes of Liphi'stius, eight in number, 

 are all situated upon a small pinnacle, and are considered to 

 represent their primitive condition, probably with justification. 



The sternum of Li'phistius is long and narrow. This is an 

 unusual form in living spiders, found only in a few six-eyed 

 forms, in which the elongation is not so marked. The 

 significance, if any, of this feature in Liphistius is obscure, 



Fig. 3. 



\ 



Ocular tubercle and eyes. 



unless it be assumed tiiat an elongated form is more closely 

 allied to a series of segments than is a shorter form. 



In the relative lengths of its legs, Liphistius is very 

 unusual. The fourth pair is the longest, then the second, 

 then the third, and the first pair is the shortest. In this 

 respect, as in the segmental abdomen, Liphistius resembles 

 Protolycosa, in which the length is 4"2=3'1, and, in fact, all 

 authors agree in placing Frotolycosa., as an extinct genus, 

 among the Liphistioidse. 



There seems to be no descriittion extant of the male palpus 

 of Liphistius. This is particularly unfortunate, since it is an 

 organ which, more than any other, shows variations of form 

 in different genera of spiders, and a knowledge of its structure 

 in this instance would assuredly be of the greatest interest. 



In addition to anatomical features, we can assert the primi- 

 tive nature of Liphistius on geological and geographical 



