OF AFRICA. 183 
The mentum with the front margin nearly straight. The sternal 
process long, narrow, rather acute at the tip, and bent upwards. 
Species I.—Plesiorrhina depressa, Burmeister; Gory and Perchéron pl. 21, fig. 1, 
(Gnathocera d.). 
Syn.—Gn. Cleryi, Dej. Cat.; and Gn. tristis, Buquet. 
Species I1.— Plesiorrhina cincta, Burmeister ; Voet, Olivier, Herbst, Schonherr (Cetonia c.). 
Syn.—Cetonia tenia, Pal. Beauy. ; Gory and Perchéron, pl. 21, fig. 4. 
Sprcirs I]1].—Plesiorrhina plana, Burmeister; Wiedemann, Germar Mag. 4, 145, 
(Cet. p.). 
Syn.—Coryphe Herschelii, MacLeay, Cet. Soc. Afr., p. 31. 
Species 1V.—Plesiorrhina mediana, Westw. Plate 46, fig. 2. Supra nigra, pronoti 
lateribus fasciaque tenui mediana elytrorum corporeque subtus cum femoribus fulvis. 
Long. corp. lin. 8. Inhabits Cape Palmas, Mr. Savage. In the collection of the 
Rev. F. W. Hope. 
The upper surface is black, moderately shining, and very delicately punctured ; the front 
margin of the clypeus is very slightly emarginate ; the prothorax has a very slender yellow 
margin on each side, within which the disc is obliquely strigose; the elytra are black and 
depressed, witha slender, nearly straight, fulvous transverse fascia, interrupted by the suture ; 
the epimera are fulvous; the podex black, with a fulvous patch on each side 3 the underside of 
the body entirely fulvous (except a slight dash of black at the base of the abdominal segments, 
on each side) ; the femoraare fulvous, and the tibie and tarsi black. 
Species V.—Plesiorrhina abbreviata, Burmeister, Fabricius, (Cetonia a.) 
Syvn.— Gnathocera flavo-succineta, Gory and Perchéron, pl. 22, fig. 2. 
This species varies greatly in the colour of the prothorax, which 
in some specimens is entirely black, in others entirely red, and in 
some is red with a very large black discoidal patch. All these 
varieties are contained in the collection of the Rev. F. W. Hope, 
the first being Jabelled with the name of ‘ Cingulata Gory,” and 
from Guinea. Burmeister, however, describes that species (H—b. d. 
Ent. p. 561,) under the genus Anochilia, and as a native of 
Madagascar. 
HETERORHINA, Westwood, ante, p. 132. 
The great diversity in the armature of the head of the males in 
the species associated under this group, appears to me to be a 
sufficient proof of the comparative unimportance of such a character 
for the establishment of genera to be founded thereupon. Dr. Bur- 
meister, in his Handbuch der Entomologie, III., p. 216 et seq., has, 
on the contrary, not only adopted the genus Diceros as distinct from 
_the group which he ealls Coryphocera (comprising most of my 
Heterorhine), but has also raised the Gnathocera MacLeay, of 
Gory and Perchéron (my Heterorhina dives), to the rank of a 
genus, under the name of Mystroceros Diardi, whilst he has sunk 
the Trigonophori into a section of his Coryphocera. In the 
appendix to his volume, p. 790, he has reduced Mystroceros to a 
species of Diceros. The opinion, however, which | formerly expressed 
