178 



Gynandry in Arachnida 



angular prominence directed outwards, and ending in a small pointed apophysis, a 

 little distance from which is a small, black, sharp-pointed, slightly curved spine, 

 directed downwards. In the abnormal specimen both palpi are without the angular 

 prominence, possessing only the curved spine ; the right [tibia] ^ is equal in length 

 to the patella ; the left [tibia] i is in normal proportion, but towards the extremity 

 has an irregular false articulation.. ..The epigyne is imperfectly formed but all the 

 details may be distinctly traced. 



It will be observed that the sexual development is everywhere im- 

 perfect, and that the two halves are sexually dissimilar. Both palps 

 superficially resemble a normal male palp, but neither is fully developed. 

 The right palp, for instance, is farther from the normal than the left, as 

 is indicated by the form of the tibial joint, which makes an approach to 

 the dimensions of the normal female palpail tibia. If the explanation of 

 the arrest of male development be the presence of a female element, it 

 is stronger on the right than on the left. 



Similarly the genital area has a general resemblance to that of the 

 normal female (so much so that Falconer as above quoted calls it an 

 epigyne), slightly imperfect on the right and still less perfect on the left. 

 If a male element is the disturbing cause, it is stronger on the left than 

 on the right. 



This state of things may be represented diagrammatically thus : 



Anterior 



Left 



M.F. 



M.Fo 



F2M2 j FsMi 



Right 



Posterior 



Here M and F represent the male and female element respectively, 

 the subscript figures varying degrees of influence, of which the figures 

 may or may not be a measure. 



iii. The following British records stand in the names of the Rev. O. 

 Pickard Cambridge and Dr A. Randell Jackson. 



Hilaira excisa Cb. Cambridge : Proc. Dorset, etc., Field Club, 1902, 

 p. 21. 



Adults of both sexes found near Glamorgan 2 and sent to me by Dr A. R. Jackson 

 in 1901. Among them was a remai-kable bisexual form. One of the palpi was that 

 of the male spider, the other that of the female ; the form of the caput was that of 



1 'Palpus' in the original ; obviously a slip of the pen. 



'■^ I quote verbatim. The specimen was actually taken on Maendy Hill, near Ystrad in 

 the Rhondda valley. 



