Sexual Dimorphism in the Butelid genus Parastasia. 481 



difference already pointed out by Dr. Ohaus, occurs in the 

 propygidium, which in the female has a peculiar micro- 

 scopic structure producing a dull sooty or velvety surface, 

 while in the male it is rather shining and does not differ 

 in structure from the rest of the surface of the abdomen. 

 Another slight difference, interesting as throwing light 

 upon P. canaliculata, is that the elytra of the female have 

 a distinct depression limited by the hinder border of the 

 pale fascia, giving this the appearance of being partly 

 elevated above the general level. 



In a new species very near these the female is dis- 

 tinguished by a very slight opaque area bordering the 

 scutellum, recalling both the opaque propygidium of the 

 same sex in the last species and the scutellar grooves of 

 P. canalieulata. It also differs from the male both in the 

 sculpture of the propygidium and of the elytrat and in the 

 form of the markings. 



Parastasia hirmana, sp. n. (Plate XVII, figs. 3 and 4.) 



Nigra, nitida, elytris fulvo-raacnlatis, corpore subtus fulvo-hirto ; 

 capite grosse punctato, quadridentato ; prothorace hand dense, antice 

 grossius, punctato, ntrinque bifoveolato ; scutello fere impiinctato ; 

 pygidio et propygidio dense striolato, illo bifoveolato ; tarsonim 

 niedionnn et posticorum unguibus externis profunda bifidis ; 

 ^ elytris subtiliter sublineato-punctatis utroque macula humerali 

 '^'-formi punctaque parva apicali flavis ornate ; 5 elytris politissiniis, 

 impunctatis, macula superiori expansa, ad margines basaleni 

 scutellarem et suturalem attingente ; prope scutellum margine tenui 

 opaco ; propygidio subtilissime striolato. Long. 22 m.m. 

 Hab. Burma (Boivring) ; Yunnan (Oberthilr). 



This species is intermediate in general appearance and 

 the character of its markings between the two previous 

 ones and is interesting as combining the sexual distinctions 

 of a number of allied forms. In the expansion of the 

 yellow fascia in the female it resembles the next species. 



P. hasalis, Cand., of which the sexes, regarded as specifi- 

 cally diflerent by that author, have been associated by 

 Dr. Ohaus, exhibits many differences. The female, as is 

 very generally the case in the genus, has a somewhat 

 different form owing to its greater parallel-sidedness, the 

 elytra, unlike those of the male, are almost entirely 

 unpunctured and the red humeral band extends to the 

 middle, whereas in the male it is shorter and more inter- 



TRANS. ENT. SOC. LOND. 1899. — PART IV. (DEC.) 32 



