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HELIOCOPRIS MOUHOTUS AND DOMINUS 
By D. SHARP, M.A., F.R.S. 
CAMBRIDGE, NOVEMBER 12, I9O3 
T hese two forms of Coprldae are amongst the largest of insects, and 
yet very little is known about them. In consequence of this, and 
also, perhaps, of a mistake made by the late Signor Fea, the idea has 
arisen that the two names are merely synonyms. Although this is not the 
case, it is probable that the two are really one species, for though it is not quite 
certain, I think it highly probable that H. mouhotus is a discontinuous variety 
of H. dominu^ which is only produced in certain localities and under certain 
conditions.* 
The following are the chief points that have been ascertained. In 1868, 
the late H. W. Bates described^ Heliocopris domina from Assam. He 
distinguishes two forms ; a large male having four horns or prominences on 
the head, and a smaller male differing chiefly in having the horns of a smaller 
size and the sexual protuberance of the thorax smaller. The female was not 
known to Bates. 
In 1878, I described Heliocopris mouhotus from Cochin China.^ In this 
case I had three forms before me ; a large form of the male having two horns 
on the head, and a great sexual protuberance on the thorax ; a smaller male 
destitute of the two large horns, but having a transverse central elevation on 
the head, the extremity on either side being prolonged and acute ; the female 
was described as possessing the structure of the head usual in that sex in the 
genus. 
In 1897, the late Signor Fea figured the large male of H. mouhotus^ 
calling it, however, H, dominus^ Bates. Since then little has been written about 
these insects, but I have received letters enquiring whether H, dominus and 
H. mouhotus are the same thing or not. 
I. The French biologists object to the term ‘discontinuous’ and prefer ‘abrupt’ brusque'), and I think, are 
right in this. 
2. Col. Hefte IV, p. 88. 
3. Ent. Mo. Mag. XV, p. 155. 
4. Fea, Viaggio Zool. in Birmania, p. 168. 
