1910] The Palpi of Male Spiders 179 



But the most remarkable feature is an elbowed structure on the 

 mesal aspect at the base of the bulb (Fig. 17). The fact that 

 the ejaculatory duct can be traced throughout the length of this 

 elbowed structure gave the first definite clew to the relations 

 of the parts of the bulb. The part containing the ejaculatory 

 duct evidently pertains to the apical division of the bulb, 

 although it appears to arise from the base of the bulb. 



When the bulb oi Aranea circulata is expanded and untwisted, 

 as occurs in the process of expansion, the relation of the parts 

 is more easily seen. Figures 18 and 19 represent two views of 

 a preparation of this kind. If Figure 19 be studied it will be 

 seen that the relations of parts are essentially the same as in 

 Aranea frondosa (Fig. 14); the basal hasmatodocha, subtegulum, 

 and tegulum follow in the same sequence ; the median apophysis 

 and the conductor project from beneath the tegulum in the cor- 

 responding positions, and the elbowed structure, which in the 

 unexpanded bulb appears to arise at the base of the bulb is 

 here clearly seen to be the embolic subdivision of the bulb. 

 The most remarkable differences are the lack of a prominent 

 distal haematodocha and the fact that the radix (Fig. 19, ra.) and 

 stipes (Fig. 19, st.) are each a complete cylinder, instead of 

 merely forming one face of the wall of a segment of the apical 

 division, as in Aranea frondosa. At the distal end of the stipes, 

 between this part and the embolus and the terminal apophysis, 

 there is a vestigial distal h^matodocha (Fig. 18. d. h.). 



In this species there is an apophysis which like the median 

 apophysis is joined by a flexible articulation to the tegulum 

 within the cuplike cavity formed by the distal margin of the 

 tegulum (Fig. 17 and 19, p. m. a.); this may be termed the 

 paramedian apophysis. As I have not found this apophysis in 

 other palpi, I do not consider it a fundamental part. 



The Palpus of Aranea Gigas. — The preceding species, 

 Aranea circulata, and several others, have been separated from 

 Aranea by Pickard-Cambridge and placed in the resurrected 

 genus Eriophora of Simon. The peculiar form of the genital 

 bulb in Aranea circulata appears to sustain this separation. But 

 in the palpus of Aranea gigas (Fig. 20 and 21) we find a form in- 

 termediate between the aranea type and what may be termed 

 the eriophora type. 



In the unexpanded bulb of Aranea gigas (Fig. 20) the parts 

 are twisted so as to render the basal haematodocha conspicuous 



