NEW ENDOMYCHIDAE AND EROTYLIDAE 519 



shall therefore attempt here to define the species as they now 

 appear to me to be divisible. 



Montrouzier's characters of E. immaculatus are negative , he 

 apparently did not recognise different species among the E?icymo?is 

 with blue, greenish or violet elytra and yellow thoraces; it will 

 be necessary, therefore, to retain his name for the species in 

 which the positive characters given for the two following species 

 do not occur ; in E. immaculatus the thorax is nearly quadrate, 

 and but slightly angulated in the middle; the elytra are ellipti- 

 cal, strongly swollen without the margin being much expanded, 

 the elytra in the middle being usually wider than the margin. 

 I have not found a male of this form with toothed front tibiae 

 and believe them not to be so, the legs are wholly black or the 

 femora are yellow at the base. 



Herr Dohrn has not given any character by which I can 

 ascertain that the species he has described as E. Gerstaeckeri is 

 different from E. immaculatus. 



It is widely spread , and was found by Doct. 0. Beccari and 

 Mr. L. M. D'Albertis at Fly River, Sorong, Mansinam and other 

 localities in New Guinea, and a variety with the thorax black 

 at Hatam. 



4. Encymon ruficollis, Kiksch. 



This species is very close to E. immaculatus, but has usually 

 a transverse thorax and the elytra are not so swollen, and have 

 their margins expanded. 



The true characters are however sexual and very inte- 

 resting. The male in this species has the head furnished with 

 a stridulating file on the crown formed of fine transverse 

 striae, the front edge of the thorax in this sex .having a 

 small fossa corresponding to an internal projection , for the 

 purpose of rasping the file. This apparatus does not exist 

 in either of the allied species, although the fossa is feebly 

 present in some specimens, there are no corresponding striae. 

 Moreover in males of E. ruficollis the intermediate femora 



