Species of Tropical African Sollfugae. 2G9 



of this year from Natal, lie says : — " With regard to the 

 stridulation of Solpwjd, I imist admit tliat I am ahnost 

 becoming sceptical about it, at least in the species with which 

 I am acquainted, for, though I have examined them carefully, 

 on no occasion have I been able to detect any signs of stridu- 

 lation, even when they have been persistently annoyed. And, 

 moreover, I find it is impossible to produce it artilicially by 

 rubbing the chelaj together. Is it not possible that the striaa 

 [fine u|)standing ridges] might be useful in compressing food 

 for the extraction of the juices'?" 



Touching the function of the palpi, and commenting upon 

 Hutton's observation showing that they are used as suckers 

 in climbing sli|)pery places, he remarks : — " As far as I can 

 see they seem to be used merely as tactile or, perhaps, auditory 

 organs. They are usually carried well forward just off the 

 ground, and appear to be highly sensitive." But in a sub- 

 sequent letter he adds: — '' 1 have been further investigating 

 the use of the terminal organ on the palpus, and am fully 

 satisfied that liutton was right in supposing it to be a sucker. 

 I first noticed this when teasing a specimen with a straw and 

 trying to make it stridulate. The creature struck sharply at 

 the straw with its palpi, pulling it slightly towards itself. 

 Wondering how it was able to grasp the object, I tried again, 

 and distinctly saw a gelatinous fan-shaped sucker protruding 



from the palpal knob and sticking firmly to the straw 



I feel tolerably sure that the chief use of the sucker, which is 

 evidently a very delicate organ, is for the purpose of grasping 

 prey and conveying it to the mandibles. Owing to the 

 extreme rapidity of their movements, it is almost impossible 

 to observe exactly how they catch insects, but my general 

 impression has always been that the prey is first caught by 

 the palpi, and not by the mandibles direct." Specimens 

 kept in captivity " devoured all sorts of small insects most 

 voraciously, and, while eating, in addition to moving their 

 nipper-like mandibles vertically, they also moved them alter- 

 nately backwards and forwards in a horizontal direction." 



With regard to general habits it is interesting to note that 

 species of the same genus, Solpuga, are either diurnal or 

 nocturnal. For example, Mr. Marshall was informed by a 

 man " that when he was recently encamped at Hartley Hills 

 he was forced to move his tent on account of its being over- 

 run by a number of enormous spiders, evidently, from his 

 description, a large Solpuga [probably S. Darling ii\, which 

 came in at night one at a time, attracted apparently by the 

 light, and simply flew about it at lightning speed." On the 

 other hand, Mr. Marshall writes: " When walking into Hartley 



