BRITISH SPECIES OF PHALANGIDEA OR HARVEST MEN. 169 



above as below ; usually 8 above and 5 or 6 beneath are traceable. 

 Some of the upper ones are, owing to the crushing up above 

 mentioned, indistinct, and scarcely distinguishable from the thorax. 

 Underneath, the anterior segment is usually prolonged between the 

 basal joints of the legs and forms a quasi-sternum, which we may call 

 the genital plate. It covers the genital aperture, which is thus more 

 or less close to the mouth parts. The posterior segment contains 

 the anal aperture. 



Eyes two ; usually close together, on an eminence of the caput. 



Sternum (properly so called), small and usually hidden beneath 

 the anterior portion of the genital plate ; in front of the sternum 

 is the labium, over which on each side extend the maxillae of the 

 1st and 2nd pairs of legs, by which it is more or less covered. 



Maxillae. These are differently formed lobes springing from the 

 basal joints of the palpi and two anterior pairs of legs. There are 

 3 pairs of these, one pair belonging to the palpi and a pair each to 

 the 1st and 2nd pairs of legs. Above the first pair of maxillae 

 between the falces is a small pointed portion of structure called the 

 epistoma apparently designed to close-in the mouth parts above. 



Spiracular openings. Two ; one on each side beneath the first 

 abdominal segment, usually concealed by a fold of the epidermis 

 urderneath the COXEG of the fourth pair of legs. 



Falces. Two ; projecting in front beneath the caput, three- 

 jointed, the 3rd (or extreme) joint forming in opposition to a 

 projection, or prolongation of the second joint, a crab's claw or 

 pinchers, similar to that of the scorpions and chelifers. 



Palpi. Two ; close in front of the legs, each consisting of 

 5 joints, or, counting the basal joint, of which the maxillae form a 

 portion, 6 i. axillary, ii. humeral, iii. cubital, iv. radial, v. digital, 

 the last ending with a single claw. 



Legs, seven-jointed i. coxal, ii. exinguinal, iii. femoral, iv. genual, 

 v. tibial, vi. metatarsal, vii. tarsal ; the last always more or less 

 minutely subdivided, and ending with one or two, rarely pectinated, 

 claws. On each side of the caput on the margin just above the 

 basal joints of the first pair of legs, is, in most of the Plialangidea, 



