PAPERS ON SPIDERS 575 



latter form a continuous series lying between Drapetisca and 

 GoJigylidiiim, in which the predominating characters are what 

 I should be disposed to call Nerienine, as distinguished from 

 Linyphiine. 



At the head of this series — so near to Linyphia as hardly to 

 be included in the present group — is the genus Mengia, which 

 is very closely allied to Drapetisca. They bear pretty much 

 the same relationship to each other as Linyphia ( Helophora) 

 insignis Bl. bears to L. mojitana Clk., but the difference is not 

 nearly so great, as a glance at the copulatory organs will 

 show. To be consistent, whoever includes insignis in the 

 genus Linyphia would naturally assign the two species of 

 Mengia to Drapetisca. They differ from Drapetisca in having 

 no femoral spines, but that is a difference which exists within 

 the genus LMiyphia. Mengia, it is true, has but four outer 

 falcal teeth, while Drapetisca has five ; but in the latter case 

 the first is small and abnormally near the base of the fang, so 

 that it may be regarded as adventitious. The other four 

 resemble those of Mengia, and are similarly placed. Never- 

 theless I separate the two genera on the strength of differences 

 in the form of the maxillae, which are more quadrate in 

 Drapetisca and thickened on the inner margin. 



Four is also the number of outer teeth in affi?iis Bl. and 

 nigricauda Cb., but it is a mere numerical coincidence, for in 

 this case it is the four characteristic of Erigone and its allies, 

 of which the fourth is usually the largest, and certainly never 

 the least as it is in Mengia. As a matter of fact Trneticus 

 affinis Bl. is undoubtedly congeneric with the spider hitherto 

 generally known as Gongylidium graniinicola Sund., while 

 nigricauda Cb. only fails to be a Gongylidium (sensu stricto) 

 by reason of the nature and disposition of the leg spines. 

 Thus, oddly enough, Ttnetictis affinis, which has furnished a 

 name for the whole group, must be removed to a considerable 

 distance from its quondam associates. 



On account of the characteristic leg spines of nigricauda 

 (two dorsal on each tibia ; black, short and slightly curved) 



