1910] The Palpi of Male Spiders 175 



the ventral aspect of the proximal segments and the lateral 

 aspect of the bulb. 



The proximal segments of the palpus. — This account of the 

 palpi of male spiders is devoted almost entirely to a discussion 

 of the parts of the tarsus, the proximal segments being well- 

 understood; there are, however, a few features of these segments 

 in the aranea type that merit attention here. 



Upon the coxa there is a prominent spur, the coxal spur 

 (Fig. 12, c. s.)\ and upon the inner side of the. femur near its 

 base, there is a groove, the femoral groove, into which the coxal 

 spur fits when the palpus is extended forward. The presence or 

 absence of this spur and groove is an important generic char- 

 acteristic in the Araneiuce. 



The patella bears two prominent spines at its apex (Fig. 12, 

 p.). This is also true in the males of several other genera; 

 but in the greater number of genera of the Araneinae there is 

 only a single spine in this position. 



The most striking feature of the tibia is its shortness, 

 being of about the same length as the patella. 



The tarsus. — As in Linyphia, the tarsus of Aranea consists 

 of two parts; the cymbium and the paracymbium. But in 

 Aranea the paracymbium (Fig. 13, p. c.) is merely a prominent 

 apophysis arising from the base of the cymbium and is not 

 articulated with the cymbium by a movable joint as in Linyphia 

 and in Pachygnatha. The alveolus is much more extended than 

 it is in Linyphia; here it occupies nearly the whole length of the 

 cymbium (Fig. 13, a.). 



The unexpanded bulb. — In the unexpanded bulb of Aranea 

 frondosa, the subtegulum (Fig. 12, 5. t3g.), tegulum (Fig. 12, 

 teg.), and a terminal lobe of the apical division of the bulb, 

 bearing a long and slender terminal apophysis (Fig. 12, /. a.) are 

 visible. Two prominent appendages can also be seen; the 

 median apophysis (Fig. 12, m. a.) and the conductor (Fig. 12,. 

 con.). 



The expanded bulb. — Two figures of the expanded bulb are 

 given here; Figure 13 represents the lateral aspect of the bulb, 

 the aspect that is exposed when the bulb is not expanded; and 

 Figure 14, the mesal as]:)cct, the one that is next the cymbium 

 in the unexpanded bulb. 



The basal hcematodocha is essentially the same as in Liny- 

 phia (Fig. 13 and 14, b. h.). 



