Stridulating-organ in Mygalomorph Spiders. 40 



examine a single specimen (the typical male) of M. auro- 

 nitens, Keyserling. There is no trace of this structure in 

 the typical specimen (a female) of M. pantherina, Keyserling*, 

 which is supposed by Pocock to be the female of M. auro- 

 nitens. It is possible, however, that this organ is confined 

 to the one sex. 



Euphrictus, gen. nov. 



Anterior row of eyes slightly procurved, the posterior row 

 almost straight. Cephalothoracic fovea minute and pro- 

 curved. Labium armed with many spinules (the spinules are 

 more numerous than is represented in tig. 4), the maxillaj 



Fie:. 1. 



Mandible of Selenogxjrus aureus, Pocock, from the inner side. 

 Fisr. 2. 



Mandible of Euphrictus spinosus, sp. n., from the inner side. 



also spinulose. Posterior sigillse of sternum of small size, 

 widely separated from one another and separated by about 

 twice their length from the margin of the sternum. Inner 

 surfaces of the mandibles furnished with a stridulating-organ 



* T. c. p. 18. 



