THE SPIDEKS OF EPPING FOREST. 185 



Sternal Plates. These are two strong chitinous pieces placed 

 below the cephalo-thorax, one between the coxal joints 

 of the palpi, the other between the coxae of the legs. 

 The former is known as the Labium, the latter as the 

 Sternum. The Labium is a small plate, usually of a 

 somewhat oblong or semi-oval shape, sometimes plane, 

 at other times having its anterior edge turned outwards 

 or thickened along its external surface, this form being 

 known as recurved. The Sternum is a rather large plate, 

 usually more or less oval or cordiform, which occupies 

 the central portion of the inferior surface of the cephalo- 

 thorax. To this structure the true legs are attached. 

 In a few cases projecting portions of the sternum pass 

 beyond the attachments of the coxae, thus forming a 

 kind of socket for the reception of each leg. 



Falces. The falces are a pair of appendages situated beneath 

 the anterior extremity of the cephalo-thorax. Each falx 

 consists of a stout basal joint surmounted by a movable 

 fang, this latter being pierced by a channel whose open- 

 ing is near the point of the fang. Connected with each 

 channel is a poison gland, sometimes placed within the 

 basal joint, sometimes within the cephalo-thorax and 

 sometimes parti}' in each. Upon the external surface 

 of the basal joint is often found a smooth raised portion 

 or basal protuberance, and in some species the falx is 

 externally striated. This structure is apparently 

 employed as a stridulating organ, being actuated in this 

 capacit}' by a process upon the inner surface of tiie 

 palpus. The fang, when at rest, lies in a depression at 

 the extremity of the basal joint, known as the fang-groove : 

 this latter is often provided, at one or both of its edges 

 with teeth or denticulations. The basal joint is sometimes 

 furnished towards its extremity with a dense tuft of 

 hairs, known as a scopula. 



Palpi. The palpi are a pair of limbs which are attached to the 

 underside of the cephalo-thorax, one upon each side of 

 the labium. Each palpus consists primarily of five 

 distinct joints, Coxa, Trochanter, Femur, Tibia and Tarsus. 

 These parts are also known amongst various authors as 

 exinguinal, humeral, cubital, radial and digital joints 



