98 Mr. M. Burr — Notes on the Forficularia. 



segment is ample, the hinder border rounded ; at the hinder 

 border in the middle there are two very stout, long, elevated 

 tubercles, pointing upwards and obliquely outwards, truncated 

 at the apex. Penultimate ventral segment large, rounded, 

 covering the ultimate segment except at the corners. 



Pygidium visible from beneath, short, conical, emarginate 

 at the apex. 



Forceps with the branches S short, stout, strongly de- 

 pressed and dilated at the base, the inner margin of this 

 dilated part is strongly toothed ; at half their length the 

 branches are cylindrical and curved inwards in a semicircle, 

 the apices are pointed but do not meet ; the inner margin of 

 this curved part is denticulated. 



The whole of the abdomen, tubercles, and forceps are 

 thickly coated with a short dense testaceous pubescence. 



Patria. Sarawak, Kuching, Dec. 19th, 1899, 1 <$ ; Pan- 

 kalan Ampat, May 1899, 1 <?. 



This remarkable earwig is very distinct from any form 

 familiar to me. The male from Pankalan Ampat presents a 

 curious form of aberration. The right branch of the forceps 

 is scarcely developed, very short, almost straight, bent slightly 

 downwards and inwards, with no sign of teeth or serrulation ; 

 the left branch is not fully developed, the deuticulation of the 

 curved part being wanting. This arrest of development is 

 well known to occur in Forficularia, and is often called 

 hermaphroditism or gynandromorphism ; but it is extremely 

 doubtful whether this is ever really the case. In the specimens 

 which 1 have examined the normal number of segments of 

 the male — that is, nine — are visible ; in the female only seven 

 segments of the abdomen are visible. I have in my collec- 

 tion two specimens of Chelisoches morio, Fabr., in which the 

 leit branch is that of the male in the form and the right is 

 that of the female, and these I have recorded elsewhere* as 

 heimaphrodites ; but it is more probable that the phenomenon 

 is due to ai rested development, owing to want of nourish- 

 ment or some accident. I have a male of Pygidicrana 

 marmoricrura in which both branches of the forceps are 

 abnormal, being nearly straight and unusually pubescent ; 

 this is certainly an aberration, and not a regular dimorphic 

 torm. The specimen of Ck. Hercules in which the right 

 branch is maltormed is noticeably smaller than the other 

 fully developed male, and it may well be due to defective 

 nourishment. 



* Ent. Month. Mag. 1897, p. 147. 



