The External Anatomy of Spiders 



I n this species there is an apophysis, which like the median apophysis, is joined 

 by a flexible articulation to the tegulum within the cup-like cavity formed by the 

 distal margin of the tegulum (Figs. 109 and 1 1 1, p. m. a.); this may be termed the 

 paramedian apophysis. As 1 have not found this apophysis in other palpi, I do 

 not consider it a fundamental part. 



The Palpus of Aranea Gigas. — The preceding species, Eriophora 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 gen- 

 ital bulb in Aranea circulata appears to sustain this separation. Rut in the palpus 

 of Aranea gigas (Figs. 1 12 and 1 13) we find a form intermediate between the aranea 

 type and what may be termed the eriophora type. 



In the unexpanded bulb of Aranea gigas (Fig. 112) the parts are twisted so 

 as to render the basal haematodocha conspicuous as in Eriophora circulata; but 

 otherwise there is little similarity in appearance to either this species or to Aranea 

 frondosa. 



/>. c. - 



con. 



pet.- 



^IS^|-"'' 



Fig. 113. 

 EXPANDED BULB OF ARANEA GIGAS 



Fig. 114. EXPANDED BULB 

 OF DOLOMEDES FONTANUS 



In the expanded bulb (Fig. 113) it can be seen that the embolic subdivision, 

 is intermediate in form between the two types, resembling the aranea type in 

 having a large distal haematodocha and a well-developed median subterminal 

 apophysis; and resembling the eriophora type in the form of the embolus, which 

 is lamelliform (Fig. 1 13, 2). 



The Pisaurid Type of Palpus. — In the family Pisauridae 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 Dolomcdes 

 jontanus (Figs. 1 14 and 1 1 5) may be taken as an example of this type. 



A study of an expanded bulb of this species (Fig. 114) reveals the following 

 characteristics: There is a well developed petiole of the bulb (Fig. 1 14, pet.), which 

 in this species consists of two nodes with an unchitinized internode. The sub- 

 tegulum bears very prominent anelli (Fig. 1 14, an), which are described in a later 

 paragraph. The median apophysis is prominent (Fig. 1 14, m. a.). The conductor 

 (Fig. 1 14, con.) is extremely membranous. The radix and the stipes are not 

 developed as distinct segments. The etkbolus is of the spiral type (Fig. 1 14, emb.) 



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