40 
tere leevibus nitidissimis, his stria suturali fortiter impressis ; 
corpore subtus dense hirsuto ; pygidio fere glabro. Long., 
9 1.; lat., 54 1. 
This extraordinary species is instantly distinguishable from its 
described congeners by the remarkable armature of its prothorax 
which consists of three somewhat slender horns of about equal 
length, each of them about as long as the prothorax is wide. Its 
black head prothorax and pygidium are also notable. The per- 
pendicular front of its head viewed from in front is flattened,— 
not concave as in that of P. mullerianus,—and is almost of semi- 
circular shape, the chord of the semicircle (which however is 
slightly arched) forming its upper outline. 
Gascoigne District, W. Australia; in the collection of Mr. 
French. 
P. trifidus, sp. nov. Mas. Latus; sat nitidus ; rufo-brunneus; 
capite antice perpendiculari, parte perpendiculari concavo ; 
antennarum flabello elongato ; hujus articulis singulis quam 
articuli ceteri conjuncti multo longioribus ; prothorace spar- 
sim subtiliter (parte excavata magis crasse) punctulato, 
cornubus 3 armatis (his quam prothoracis latitudo fere triplo 
brevioribus, cornu antico valde trifido, lateralibus crassissi- 
mis sed apicem versus sat gracilibus); scutello sparsim 
punctulato; elytris inequaliter striatis, striis crebre sat 
fortiter punctulatis, interstitiis sparsim ineequaliter punctu- 
latis ; corpore subtus dense hirsuto ; pygidio crebre (apicem 
versus sparsissime) punctulato. Long., 12 1.; lat., 7 1. 
This species is easily recognisable by the armature of its pro- 
thorax ; the front horn is directed forward over the head and 
turned upward at the apex which consists of three large triangu- 
lar teeth (the middle one erect, the lateral ones directed outward 
on either side); the lateral horns are placed very widely apart 
and are erect but a little curved (so as to be convergent at their 
apices), and are extremely thick at their base but in their upper 
half become slender with almost pointed apices. The striation 
of the elytra is much better defined than in P. mullerianus, 
White. 
Queensland; Darling R. district; in the collection of Mr. 
G. Masters. 
HORONOTUS. 
H., optatus, Shp. I have before me three male specimens for- 
warded by Mr. French evidently of this species. J should judge 
from the description of H. variolicollis, Fairm., that it is founded 
on the same species and must become a synonym. It seems also 
probable that my Palmerstonia minor is the female (which ap- 
pears to have been unknown to both Sharp and Fairemaire) of 
