ANATOMY OF sph^eotheeium:. 165 



cies, he has unaccountably overlooked the well-defined stridula- 

 ting-organ developed in connexion with them. This organ is 

 similar in the two species whicli I have examined, and. consists of 

 a prominent bolster-shaped swelling on the postero-external edge 

 of the second joint. This swelling occupies the entire exterior 

 margin of the joint, and shows a number of transverse parallel 

 ridges separated from one another by concave furrows. The 

 whole organ is more darkly pigmented than the adjoining parts, 

 and the crest of each ridge is occupied, by a line of nearly black 

 and exceedingly hardchitin. Opposite to this rasp-like organ, on 

 each side, the interior surface of the last tergite is slightly raised 

 into a cushion-like projection, which projection is armed with a 

 number of hard stiff chitinous points. By rapidly rubbing the 

 rasp-like organ on the second pair of accessory appendages against 

 the roughened interior surface of the last tergite, I succeeded in 

 producing a tolerably shrill note, not unlike that of the common 

 house-cricket. There can be no doubt that this is a stridulating 

 apparatus used by the males to attract the females. 



The male Splicer other ium probably rasps his limb against his 

 tergite a great deal faster than I was able to do, and produces a 

 shrill high-pitched note. As far as I know, nobody has given an 

 account of any stridulation produced by the males of this genus. 

 It would be interesting if any naturalist proceeding to, or living 

 at, the Cape were to observe the habits of the 8p}i<sr other ia, and 

 give us some account of the stridulation which is doubtless pro- 

 duced by the males. 



Observations on the mode of copulation would also be of interest. 



The third pair of accessory organs consists of two spike-shaped 

 single-jointed appendages lying between and rather posteriorly 

 to the forcipides copulatrices. These I belieye to be penes. 

 They are perforated at their extremities, and contain a central 

 cavity ; but I was not able to detect any spermatozoa or sperma- 

 tophores in the latter. When the animal is rolled up they are 

 capable of beiug applied to the generative openings on the second 

 pair of limbs; but there is no internal communication with the 

 gonads. Until the act of copulation in Sphcerotherium has been 

 observed, it is not possible to say whether these appendages 

 function as penes or not; but from their position and structure, 

 and from the fact that no other copulatory organs exist in the 

 male Sphcerotheria, whereas such are present in the allied genus 

 Glomeris, I think it highly probable that they do. 



