566 Mr. T. Vernon Wollaston on the 
(or, more strictly, perhaps, to the same cluster of types), — 
peculiar, apparently, to the islands of the Malay archi- 
pelago ; and yet I scarcely think that they conld be 
regarded as representing even distinct sections of a single 
group. At any rate, if I Avere to treat them now as such, 
I feel that the time would assuredly arrive when (as 
I have lately done with the forms which cluster around 
3Iesites) they would be separated ; and hence I have 
thought it desu-able to forestall that event by detaching 
them at once. 
With this preliminary remark, I may state that Homalo- 
trogus differs from Gloeotrogus in its type being a little 
more evidently (though at the same time very lightly) 
sculptured, and not so highly polished ; in its head being 
much narroAver, more convex, and oval (instead of flattened 
and subquadrate) ; in its eyes being consequently less 
widely separated ; in its rostrum being much longer and 
more couA^ex, and (instead of nearly parallel) with the hinder 
half comparatively slender and contracted, and Avith there- 
fore the anterior one suddenly dilated (much as in Cos- 
sonus) ; in its pi'othorax (Avhich is exceedingly eveti) being, 
if anything, squarer still, though more e\"idently constricted 
at its extreme apex ; in the last three segments of its 
abdomen being margined behind Avith a roAV of large 
punctures ; in its antennae (which are inserted conspi- 
cuously before, instead of behind, the middle of its much 
longer rostrum) having their sca2:)e straighter and less 
outAvardly curved, and only ohsolctely tnmcate toAvards the 
inner apex (and therefore Avith but a very slight tendency 
for the anguliform projection Avhich is so marked a feature 
in Gloeotrogus), and haAang their second funiculus-joint 
appreciably less shortened ; and in its legs being longer, 
Avith the femora (at any rate the posterior four) somcAvhat 
less clavate, and Avitli the tibite less abbreviated. Judging 
from the labels Avhich are appended to them, the types 
now before me (Avliich are from the collection of jNlr. 
Pascoe) Avere taken by jNIr. "Wallace in the islands of 
Coram and Batchian, of the Malay archipelago. 
82. IsOTROGUS {iiov. gen.). — This genus makes a nearer 
approach to the normal Cossonus pattern than either of 
the preceding tAvo ; yet it certainly is not identical Avith 
that group, — its extremely flattened body and unimpressed 
protliorax, and the peculiar construction of its scape 
(Avhich is biflexuose, and shoAvs a more distinct tendency 
