574 PAPERS ON SPIDERS 



The development of the paracymbium of the male palpus is 

 a characteristic feature of the Ceiitromeri. This paracymbium 

 is a chitinized branch of the tarsus, springing from its inner 

 surface near the base and outer margin, behind the attach- 

 ment of the bulb. In the Ceiitromeri the base of attachment 

 is comparatively large, and the limb is continuous with the 

 upper surface of this basal part, which in the larger species is 

 usually smooth and chitinous. In some species of lesser size 

 (notably in emptus) it is only imperfectly chitinized and more 

 or less covered with bristly hairs ; but always it has the 

 appearance of forming part of the complete crescentic sweep 

 of the limb, never breaking the outline, and indeed usually 

 produced on the side opposite to the main limb. Including 

 the whole of this circuit, the paracymbium covers about three- 

 fourths of a circle, but is much broader in the middle than at 

 either extremity, and the inner surface is concave. It is so 

 attached to the tarsal surface that when the palpus is viewed 

 from the outer side nearly the whole inner surface is visible. 



Typically the epigyne of the female presents a vulvar fovea, 

 wider than long, divided by a more or less heartshaped 

 central process. The attachment of this process is near the 

 anterior margin, the middle of which is often produced back- 

 wards so as to overlap it considerably. 



Throughout the genus two dorsal spines on each tibia is 

 the rule, the spines of the posterior legs being longer and 

 stronger (usually darker) than those on the anterior legs. 

 The femoral spines vary. For the majority of species the 

 formula is — femur i., 2 or 3 ; femur ii., i or 2 ; femora iii. and 

 iv., o or I ; but there is a small group, of which serratns Sim. 

 is the only British example, in which femur i. bears a solitary 

 spine, and the rest are spineless. The larger species have a 

 single feeble spine on each metatarsus. 



Obviously the correct systematic position of Centronierus is 

 with Porrhomma and Bathyphantes between Lephthyphantes 

 and Microneta, a series which ought not to be broken by the 

 intrusion of the remaining species now under review, The 



