APPENDIX F. ARACHNIDIANS. 237 



provided upon its anterior margin with five conical spines, varying in 

 size : seen in front, (fig. 3, b), it is elevated almost vertically from the 

 horizontal position of the first. The third joint is the longest of all, 

 slightly curved, and provided inwardly with two minute spines — one 

 above, the other below. The fourth joint is somewhat shorter than the 

 third, but is much longer than broad, subcylindrical, slightly bent, and 

 provided at its inner, anterior, and upper edge, with a prominent, conical, 

 and straight spine. The fifth joint is of the length of the fourth, but 

 slenderer, and provided anteriorly with a stout and shorter spine. Fi- 

 nally, the sixth joint is a subconical and spiny processus, moving against 

 the spine of the fifth joint, constituting a forceps, and used as such to 

 seize prey. The thoracic appendages (feet) are long and slender, espe- 

 cially the anterior and posterior pairs. The anterior pair may be readily 

 distinguished from the three others, in not being provided with hooks 

 upon their extremity. Its function is rather that of a pair of palpi than 

 that of ambulatory organs. The first and second joints are short and 

 stout ; the third, fourth, and fifth long and slender ; the fourth and fifth 

 almost equal in length, and longer than the third. Eight small joints, 

 together equal in length to the third, terminate these appendages. The 

 three others are constructed upon the same plan, all having nine joints 

 and terminal hooks, generally two in number. The first, second, and 

 third joints are similar to those of the anterior pair; the third, how- 

 ever, is the longest ; the fourth is but a little longer though slenderer 

 than the second, and slightly curved ; the fifth is much slenderer and a 

 little shorter than the third. Next come four small joints, together 

 smaller in length than the fifth, and provided upon their anterior mar- 

 gin with minute spines. The second of these four, or the seventh in 

 the series, is the longest of the four ; the third is the smallest ; the first 

 and fourth are equal in length, the latter much slenderer. Two hook- 

 like and slender spines terminate these organs. 



The abdomen is longer than the cephalothorax, oval in shape, 

 though depressed, and composed of eight very distinct segments and a 

 half, the anterior one. The stigmatiform bodies are quite conspicuous 

 above (seven pairs), and below (four pairs). The anterior half segment 

 is not seen from below. The seventh segment exhibits laterally a second 

 pair of stigmatiform bodies, less conspicuous, however, than the others. 

 The posterior segment has also faint traces of an analogous pair. The 

 two first caudal rings are very narrow ; the third is as large as the two 

 others together. The filiform appendage is very long, and composed of 

 about fifty joints. 



