Malacoderm Genera Prionocerus and Idgia. 345 
There is a pair of this species in the British Museum and 
a male in the Hope collection at Oxford. A very elongate, 
dull, greyish-green insect, with the anterior and basal mar- 
gins of the prothorax, the extreme bases of the femora, the 
abdomen, and the under surface in great part, testaceous ; 
the antenne slender, filiform ; the prothorax rugulose, the 
dark patch on the disc sometimes divided down the middle ; 
the elytra unusually long and densely, rugulosely punctate ; 
the legs slender in both sexes. 
22. Idgia cyanocephala, sp. n. 
Elongate, narrow, subparallel, moderately shining, finely 
cinereo-pubescent, and sparsely nigro-setose; cyaneous, the 
elytra and under surface greenish, the prothorax and basal 
joints of the palpi testaceous, the antenn piceous, testaceous 
at the base and tip. Head narrow, moderately produced 
anteriorly, the labrum transverse; eyes somewhat distant 
in both sexes ; antennz slender, subfiliform, joints 3 and 
4 about equal in length, 11 much longer than 10, concave 
within. Prothorax scarcely wider than the head, sinuate 
at the sides posteriorly, about as long as broad. Elytra 
elongate, subparallel, at the middle twice as wide as the 
prothorax, rounded at the tip, flattened on the disc; densely, 
rugulosely punctate, with four rows of rather prominent 
granules, the margins crenulate. Legs slender. 
$. Anterior tarsal joints 1-3 with a narrow comb along 
their inner edge ; posterior femora slightly thickened. Geni- 
tal armature (PI. XI. fig. 19): lateral lobes moderately long, 
feebly sinuate, narrowed towards apex ; median lobe stout, 
sinuate, pointed. 
Length (excl. head) 74-81, breadth 24 mm. (¢ 2.) 
Hab. Mauacca, Perak (Doherty). 
One male and two females. Smaller than the Indian 
I. viridipennis, Pic, the head narrower, the antennz slender 
and with the fourth joint as long as the third, the eyes 
larger, the elytra flattened on the disc, the fourth row of 
granules forming a distinct ridge. Compared with J. ceru- 
leiventris, which also occurs at Perak, the metallic-blue 
head, elytra, and legs and the slightly thickened posterior 
femora of the ¢ will serve to distinguish I, cyanocephala, 
23. Idgia rouyeri. 
Idgia rouyert, Pic, L’Echange, xxii. p. 43 (1906). 
Elongate, narrow (¢), broader (¢), shining, thickly 
