236 APPENDIX F. ARACHNIDIANS. 



II. TARANTULID^E. 



Thelyphonus excubitor, Girard. 



Zoology, PI. XVII, fig. 1-4. 



Spec. char. — Blackish brown above, deep chestnut beneath ; upper 

 surface of body and legs minutely granular ; beneath smooth, with scat- 

 tered minute imprinted dots. First and second articles of the palpi very 

 granular, remaining ones with a few granules and numerous imprinted, 

 dots. Caudal appendage very much developed, 'and composed of about 

 fifty joints. 



Description. — There is a very great resemblance between this species 

 and T. c/iganteus* The only striking difference which exists between 

 them is to be found in the structure of the palpi and in the length of 

 • the caudal appendage. 



The cephalothorax is elongated, narrowest anteriorly, where it assumes 

 almost a triangular shape. Its posterior margin is subtruncated, slightly 

 concave in the middle. The central portion of the anterior third of 

 the cephalothorax presents a perfectly plane surface, with a medial 

 furrow, as it were ; whilst posteriorly it is depressed, and sloping to- 

 wards the margins, the surface showing shallow depressions, one upon 

 the middle line, and more regular than the lateral one. Near the ante- 

 rior extremity, and in a subcircular depression on each side of a medial, 

 smooth, and rounded elevation, are found the ocelli, circular, large and 

 black. In advance of these ocelli, the rostrum is almost abruptly trun-. 

 cated, as seen in the centre of fig. 3. From the anterior ocelli to the 

 lateral ones extends a linear series of granules, terminating upon the tu- 

 berculous elevations, upon which are seen three yellowish ocelli grouped, 

 as exhibited in fig. 2. 



The chelicerse are robust, but very slightly bent, composed of one large 

 joint and a conical, curved, and acute spine ; to the inner side of which 

 are attached brushes of quite elongated and reddish setae. Palpi long 

 and robust, in the shape of arms, and composed of six joints. The first 

 joint is seen only from below (fig. 4, a), and exhibits a subtriangular 

 and flat surface, terminated anteriorly by a conical point. The second 

 joint is smaller than the first, scarcely to be seen viewed from below, 

 but developed upon its upper surface into a flattened and irregular disk, 



* See Gu6rins Magazin de Zoologie, 1835, Class VIII, for an illustrated mono 

 graph of the genus Thelyphonus by H. Lucas. 



