XX. ON THE OCCURRENCE OF A SYM- 

 METRICAL SPECIES OF EPISPHENUS 

 (PASSALID COLEOPTERA) IN ANNAM. 



By F. H. Gravely, D.Sc, Asst. Supdt., Zoological Survey of India. 



Of the four species of Episphenus already described, E. moorei 

 is symmetrical and appears to be confined to Ceylon, where it is 

 not very abundant. E. comptoni is slightly asymmetrical and is 

 much more abundant in Ceylon, to which island it also appears 

 to be confined. E. neelgherriensis and E. indicus are more markedly 

 asymmetrical, and appear to be confined to the Indian Peninsula, 

 where both are abundant. In Annam, as in other parts of tropi- 

 cal Continental Asia, east of the Gangetic delta, Episphenus is 

 replaced by the allied genera Ophrygonius and Aceraius, in whose 

 most highly specialized forms asymmetry is even more pro- 



Head of Episphenus a}inaniensis ( X 4~). 



nounced. The occurrence of a symmetrical species of Episphenus 

 in Annam is therefore somewhat remarkable. An almost sym- 

 metrical species of Ophrygomus has, it is true, recently been des- 

 cribed * from Tonkin, but the hair on the sides of its elytra and 

 its horizontally divided left anterior lower tooth, as well as traces 

 of asymmetr}^, clearly show that it has been derived from one of 

 the highly asymmetrical species transitional between the more 

 typical species of Ophrygonius and the genus Aceraius, and not 

 from a primtive symmetrical species like Episphenus moorei and 

 the species which I have now to describe. 



Episphenus annamensis, n. sp. 



Four specimens collected by Mr. C. Boden Kloss in Southern 

 Annam in 1918, and presented b3^ him to the Indian Museum. 

 Length 33-37 mm. 



' 0. oequalis. Mem. Iiiii. Miis. VII, 1918, p. 88, fig-, xi Ci"). 



