1910] The Palpi of Male Spiders 181 



as in Aranea circiilata; but otherwise there is Httle similarity 

 in appearance to either this species or to Aranea frondosa. 



In the expanded bulb (Fig. 21) it can be seen that the 

 emboHc subdivision, is intermediate in form between the two 

 types, resembling the aranea type in having a large distal 

 ha:matodocha and a well-developed median subterminal apo- 

 physis; and resembling the eriophora type in the form of the 

 embolus, which is lamelliform (Fig. 21, ;^). In the general view 

 (Fig. 21) the embolus is covered by the tip of the stipes. 



The Pisaurid Type of Palpus. — In the family Pisauridas 

 there is a type of palpus which, while it resembles the aranea 

 type in its more general features, differs from that type in several 

 important particulars. The palpus of Dolomedes fontanus 

 (Fig. 22 and 23) may be taken as an example of this type. 



A study of an expanded bulb of this species (Fig. 22) 

 reveals the following characteristics : There is a well developed 

 petiole of the bulb (Fig. 22, pet.), which, in this species, consists 

 of two nodes with an unchitinized internode. The subtegulum 

 bears very prominent anelli (Fig. 22, an.), which are described 

 in a later paragraph. The median apophysis is prominent 

 (Fig. 22, m. a.). The conductor (Fig. 22, con.) is extremely 

 membranous. The radix and the stipes are not developed as 

 distinct segments. The embolus is of the spiral type (Fig. 22, 

 emh.) The terminal apophysis is modified into an organ for the 

 support of the embolus (Fig. 22, Jul.), which may be termed the 

 fulcrum of the embolus. This type of terminal apophysis has 

 been termed, incorrectly, the conductor. The true conductor 

 in this species, as in all others studied, is an organ whose func- 

 tion is to protect the tip of the embolus in the unexpanded bulb. 

 At the base of the terminal apophysis, at the point where the 

 embolus arises, there is a lamelliform lateral subterminal apo- 

 physis (Fig. 22, /. St. a.). 



In the unexpanded bulb (Fig. 23), the long embolus makes a 

 curve in the distal end of the alveolus beyond the end of the 

 bulb. The fulcrum is applied against the embolus on its con- 

 cave side, and has a furrow on its distal face within which the 

 embolus rests. The distal part of the conductor is wrapped 

 about the tip of the combined embolus and fulcrum, serving, 

 as in all other cases observed, as a protection to the tip of the 

 embolus. 



