106 F. H. Gravely. P} 
The three species of this genus may be recognised as follows: — 
l. Head entirely smooth and polished; outer tubereles long and simply 
truneate. 2! 2 Ra 2 RR Eee EEE H. glaber, n. sp. 
— Head more or less rugose in front; outer tubercles much shorter, 
not Simply Truncater... 2. Wer Se a 2 
2. Both outer tubercles composed of two blunt denticles, scars of pro- 
notum without punctures or hair. ..H.zmpar, KUWERT, 1898, p. 318. 
— Inner denticle of right outer tuberele obsolete, scars of pronotum 
with hair-bearing punctures....... H. gracilis (HELLER 1910, p. 16). 
It is possible that Zaches infantılis and puerilis, KAUP (1871, p. 48), 
also belong to this genus. 
Hyperplesthenus glaber, n. sp. 
Described from a single specimen from New Guinea in the British 
Museum collection. 
Length 40,5 mm. The anterior margin of the labrum is slichtly 
concave and the sides are straight and parallel; the angles are rounded, 
the left one being scarcely more prominent than the rieht. The upper 
tooth of both mandibles is obtuse and not very strongly developped; 
Head of Hyperplesthenus glaber, n. sp. ><4. 
the three terminal teeth and the anterior lower tooth are conical, well- 
developed and perfectly distinet one from another on both sides. The 
scars of the mentum are broad and straight; they are not united behind 
in the specimen before me. Belind them a band of fine hair- bearing 
punctures extends transversely just in front of the posterior margin, 
uniting a pair of more coarsely punctured areas which occupy the posterior 
angles of the mentum. The remaining surface of the mentum is polished 
