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XVII. On some Luminous Coleoptera from Ceylon. By 

 E. Ernest Green, F.E.S., Govt. Entomologist, 

 Royal Botanic Gardens, Peradeniya. 



[Read November 6th, 1912.] 



Plate LXXXVI. 



Harmatelia hilinea, Walk. 



A short note on the occasional luminosity of this beetle 

 was published in " Spolia Zeylanica," vol. vii, Part XXVIII, 

 p. 212, Aug. 1911. 



At that time I had not personally noticed any luminous 

 phenomena connected with this insect, although many 

 living examples of Harmatelia had been under observa- 

 tion. But, in September 1911, two specimens, caught in 

 the Peradeniya Gardens, exhibited a distinct light when 

 examined in a dark room. 



It was seen at once that the light was not confined to a 

 single area, as in most other Lampyridae, but was emitted 

 from several distinct foci on each side of the body. 

 These luminous spots appeared to be closely connected 

 with the spiracles. Eight luminous foci could be dis- 

 tinguished on each side of the abdomen, and one on each 

 side of the thorax — the latter apparently situated beneath 

 the shoulder of the elytron. When emitting the light, 

 the abdomen was slightly depressed, to expose the dorso- 

 lateral area, and, when at its brightest, the whole abdomen 

 appeared to be irradiated internally. The luminous spots 

 were more brilliant on the dorsum, but could be plainly 

 distinguished (by transmission) on the venter of the 

 insect. 



The accompanying figure (Plate LXXXVI, Fig. 1) shows, 

 diagrammatically, the position of the phosphorescent foci 

 as seen from below, the luminous spots being represented 

 in red. 



I have not yet succeeded in determining the female of 

 this beetle, and it remains uncertain whether the other 

 sex is an apterous grub-like creature, or whether it is in 

 the form of a normal beetle. 



TRANS. ENT. SOC. LOND. 1912. — PART IV. (FEB.) 



