b SCOKPIOKES. 



pair of median eyes, and on each of its antero-lateral angles with' 

 two or three large eyes, and sometimes one or two small eyes as 

 well ; the triangular area between the eye-groups is termed the 

 frontal area or the anteocular triangle. The anterior border of the 

 carapace is often notched in the middle, forming a right and left 

 frontal lobe. Mandibles chelate, consisting of three segments, the 



Fig. 1. — Carapace, chela, and mandible of Palamneeus svjammcrdami. 



a, median eyes ; b, lateral eyes ; c, frontal lobe of carapace; d, second segment 

 of mandible ; e, movable, and /, immovable finger of mandible ; g, coxa ; 

 h, trochanter ; i, humerus ; k, brachium ; /, hand; on, movable finger, 

 n, immovable finger of chela ; o, lobe of hand. 



basal small and concealed ; the second, larger and swollen, furnished 

 in front with a strong process, the immovable finger, which is 

 armed with an upper, and sometimes also with a lower, set of teeth ; 

 the third segment, the movable finger, which works in a horizontal 

 plane, is also furuished with one or two rows of teeth, an upper 

 and a lower, along its biting-edge. 



The appendages of the 2nd pair (chela) are pincer-like and move 

 for the most part in a horizontal plane ; the segments are named 

 as follows from base to tip — coxa, trochanter, humerus, brachium, 

 hand, movable finger. The coxa is freely articulated to the mem- 

 brane on each side of the mouth and acts as a jaw or maxilla ; the 

 humerus and brachium are generally furnished with granular 

 crests or leeels. For descriptive purposes the humerus is regarded 

 as set at right angles to the long axis of the body, hence it has an 

 anterior and a posterior surface ; whereas the brachium and hand 

 are regarded as resting in a line parallel to the long axis of the 

 body, hence they have an outer and an inner surface. The hand 



