and on eacli of its anterolateral angles with two, three or 

 five small lateral eyes. The ventral surface of the cephalotho- 

 rax consists of four pairs of coxal plates, or coxa, two pairs 

 of maxillary lobes and a median sternal plate or sternum. The 

 cephalothorax is furnished with five pairs of appendages, of 

 which the anterior pair, or mandibles are situated close to- 

 gether beneath the front edge of the carapace above the 

 mouth; eacli of the mandibles is armed with two fingers, 

 movable and immovable; the upper and lower edge of each 

 finger are mostly dentate. The appendages of the 2-nd pair 

 (palpi) are chelate and consist of four joints, which are na- 

 med as follows from l)ase to tip — trochanter, humerus, bra- 

 chium and hand, which is armed with an immovable and with a 

 movable digits. The digits are furnished with an armature of several 

 rows of granules, or of small teeth arranged longitudinally and 

 partly obliquely along their biting-edges. The remaining four pairs 

 of appendages, or legs consist each of six segments — trochan- 

 ter, femur, tibia, metatarsus, protarsus and tarsus; the last 

 is provided with two claws at the tip. To the articular mem- 

 brane between the matatarsus and the protarsus is attached 

 a spur, and between the protarsus and the tarsus — two, or 

 one (outside) tarsal spine; the upper side of the tarsal Joint 

 is generally produced at its distal end into a claw-lobe 

 overhanging the base of the claws. The abdomen, consists of 

 twelve distinct segments, seven (praeabdomen) of which are 

 covered from above by a tergal plate, or tergite each and 

 from beneath by a sternal plate, or sternite. The last five 

 segments are narrow, flexibly jointed together and constitute 

 with the postanal segment «the taib) (postabdomen). The 

 postanal joint, a veritable tail, consists of a usually globular 

 basal portion, the vesicle, which contains a pair of poison- 

 glands and a spiniform distal portion, the aculeus; all the 

 joints of the tail are as a rule ornamented at the sides and 

 below with elevated and usually granular keels. The first 

 four segments are furnished with eight or ten keels; the 

 5-th joint has only five complete keels. Behind the sternum 

 of the cephalothorax, on the first abdominal somite is situa- 

 ted the genital aperture, which is covered by a single, or 

 double movable lid, the genital opercula; the sternite of the 

 2-nd abdominal somite bears a pair of comblike appendages, 

 the pectines; each of the following four abdominal sternites 



