92 LUCANID^. 



than those of the female, the termmal fork of the front tibia 

 is short and abrupt and the tarsi bear rather long 3'ellow hairs 

 beneath. 



No variation of importance is at present known. 



i^. Length (with mandibles) , 80-34 mm. ; (without mandibles) 

 27-31 mm. : breadth, 12-13 mm. 



$. Length, 32-36 mm. ; breadth, 13-14 mm. 



Dabjeeling Distr. : Pedong (L. Durel). 



Type in the British Museum. 



The very feeble sexual dimorphism of this species is 

 remarkable in an insect of fairly large size. It is noteworthy 

 that there is at the same time an accentuation of the female 

 characteristic in the tubercles upon the head. The form of 

 the male mandibles seems to suggest that they may be 

 employed for some practical purpose. 



The tyj^e of D. derelictus is a female and the male was for 

 many years unknown, perhaps because it was regarded as 

 belonging to the other sex. 



31. Dorcus opacipennis. (Plate IX, figs. 10, 11.) 



Dorcus opacipennis Zang,* Deutsche Ent. Zeits. 1906, p. 184; 



Arrow, Trans. R. Ent. Soc. Lond. Ixxxiii, 1935, p. 109 ; Ann. 



Mag. Nat. Hist. (11) ii, 1938, p. 53. 

 D. svturalis Westw.,* Trans. Ent. Soc. Lond. 1871, p. 358, pi. 8, 



fig. 5 ; Wat., Ann. Mag. Nat. Hist. (5) xix, 1887, p. 289 ; Boil., 



Trans. Ent. Soc. Lond. 1913, p. 263. 

 D. rotundopimctatus Nagel,* Arb. Morph. Tax. Ent. iii, 1936, p. 209. 



Black and opaque, the jironotum and a triangular basal 

 area common to both elytra shining in the female. Moderately 

 elongate, rather parallel-sided, with fairly stout legs, the 

 middle and hind tibiae each armed with a lateral spine. The 

 cantlius produced beyond the middle of the eye. The antemia* 

 short, the joints of the club short and the seventh joint sharply 

 ])roduced. The shoulders of the elytra rounded. The pro- 

 sternum broad and rounded behind. 



$. The head is coarsely rugose, with a strong median tubercle 

 between the eyes, the canthus rounded and slightly promuient 

 in front. The mandibles are short, with a sharp internal 

 tooth and a blunt one directed upwards. The clypeal process 

 is feebly bilobed. The pronotum very smooth and shining, 

 but the sides rather narrowly opaque and densely punctured. 

 The front angles are very bluntly produced, the lateral margins 

 first a little sinuate, then straight to the lateral angle, which 

 is obtuse, and then straight again to the base. The elytra 

 are very closely ])unctured and opaque, with the exception 

 of a triangulai- basal area not extending to the shoulders nor 

 to the ends of the elytra : this area is very shining and very 

 minutely but not closely ])unctured. The front tibia is 

 iaicly strongly tootlied laterallv and forked at the end. 



