on the Species of Ti-cqj-door Spiders. 



179 



Now it will at once be perceived that the number and form of 

 the joints of the palpi, thus developed by the addition of another 

 joint, exactly correspond with the ordinary condition of the feet 

 of the spider, that is, in possessing seven joints. We have, there- 

 fore, to inquire into the anomaly of the genus Herstlia, and I 

 think I shall have no difficulty in proving that that genus has but 

 the typical number of joints. In carefully examining the ungues 

 of Actinopus while alive, I observed arising at the base of and 

 between the ungues a separate single minute spur, moveable with 

 them, and arising from a distinct moveable fleshy joint at the end 

 of the last joint of the foot. Thus the mode of insertion of these 

 ungues is totally different from that of the ungues of, for instance, 

 a beetle ; since here they have a united motion, for by touching 

 the basal spur alone they are set in action. Here then we have, 

 as it appears to me, the analogue of the additional joint of the 

 foot of Hers'dia, which instead of being a mesotarsal joint, as at 

 first supposed by M. Lucas, or as preceding the metatarsus as 

 subsequently considered by him, is shown to be an additional 

 terminal joint. The following summary of these analogies and 

 ** concordances" will therefore place the subject in a clearer light, 

 and get rid of all the supposed anomalies both in the palpi of 

 Actinopus and feet of Heradia. 



Foot. 



1. Coxa . . . 



2. Trochanter. 



3. Femur . . 



4. 1st joint . 



5. 2d joint. . 



6. 1st joint 



7. 2J joint. 



8. 3d joint. 



Foot, 



or Hanche, Sav. . 



5 or L'exinguinal . 



I Sav 



i or Le femoral, 



( Sav 



} of the ^ or Le genual, Snv. 

 i J'ibia, i^ or Le tibial, Sav. 



Foot. 



'^or Le Metatarse,^ 

 Sav 



of the 

 Tarsus,^ 



''Metatarse, Lu-^ 

 cas, in Guer. 

 Mag.de Zool. 

 Mesotarse,do., 

 in Ann. Soc. 

 Entom. de 

 France. . . . 



{Mesotarse, Lu- 

 cas, in Gu6r. 

 Mag. de Zool. 

 Metatarse, do., 

 in Annales . . 



or Pseudo-tarsus,^ 

 Westw, ordi- 

 narily conceal- 

 ed, but deve- 

 loped in Her- 

 stlia 



Tarse, Lucas, 

 in Guer. Mag. 

 de Zool. and 

 in Annales. 



Palpus. 

 Maxilla. 

 Art. axillaire. 



Humeral. 



Cubital. 

 Radial. 



Metadigital, Lucas, 



ordinarily soldered 



>■ with the digital, 



but separated in 



Actinojms $ . 



Digital, Sav. 



Pseudo - digital, 

 ]Veslw., always 

 concealed in the 

 females, but pro- 

 bably transformed 

 into the exciting 

 organ of the male. 



