576 PAPERS ON SPIDERS 



I propose the new genus Ostearius to receive it. It stands 

 very near indeed to Gongylidium. 



The remaining species agree in having five teeth on the 

 outer margin of the fang-groove. The first is situated a Httle 

 within the first half, followed by three others equidistant or 

 nearly so, gradually increasing in size. The fourth is there- 

 fore the largest, while the fifth is smallest of all, and its 

 distance from the fourth is sometimes as much as double the 

 interval between the rest. The inner teeth vary in number 

 from three to five, and are usually very small. The normal 

 armature of the legs is — two dorsal spines on each of the 

 tibiae, one on each of the genua, and a lateral spine on the 

 front side of tibia i., but some genera are defective in this 

 respect. 



OreonetMes adipatus L.K. is the type of a little group which 

 lies nearest to Mengia. The falcal teeth are quite conical, 

 straight and broad-based. It is chiefly to the strong develop- 

 ment of the copulatory organs that these spiders owe the 

 position here assigned to them, but in general structure {e.g. 

 the form of the labium) they are nearer to Linyphia than to 

 Tmeticus. 



By virtue of the development of the genitalia, Macrargus 

 rufus Wid., follows next in order ; but it is very likely that it 

 may ultimately find a place elsewhere, for Tmeticine characters 

 are more conspicuous than in some of the genera which follow. 

 For instance it differs from all its neighbours in the size of the 

 inner falcal teeth in the male. They are even larger than in 

 Tmeticus and Osfeai'tus, and may quite easily be distinguished 

 by the naked eye if the falces are looked at laterally. The 

 male also has a mamilliform tuber on the front of the falces, 

 but it is not centrally situated as in Tmeticus. 



Very near to Oreonetides in external appearance is Lepto- 

 rhoptru?n. There is however a conspicuous difference in the 

 development of the copulatory organs, which are in this genus 

 of the very simplest type. The most decisive character is the 

 form and size of the labium. There is not much differentiation 

 between the sexes except in the caput of hardii Bl, 



