740 Mr. Gilbert J. Arrow on 



impimctate and the tborax and elytra thinly and vaguely 

 punctured. There is no supplementary inner tooth to the 

 front tibia of the male, which forms a further distinction 

 between the two species, the male of ^. guianensis having 

 a small tooth upon the inner side of the terminal one. 



A pair of j^. Irasiliensis has been presented to the 

 British Museum by M. Rene Oberthiir. 



The new crenus which I have called Idiostoma has no 

 near relationship to any other form yet known and must 

 be regarded as forming a new sub-family. 



Idiostoma, gen. nov. 



Corpus crassum, ovatum : caput parvum, cornutum ; trophi 

 degenerati, labrum minutum ; maxillfe unilobatfe ; antennas 10- 

 articulatje, articulis 1-2 globosis, hirsutii?, 3-7 brevissimis, 8-10 

 clavam parvana componentibus : corpus subtus pedesque longe fulvo- 

 liirti, hsec robusti ; coxae posticae haud latse, costa stridulatoria 

 prope extremitatem externam prpeditae. 



The clypeus is very small and bidentate in front, the 

 eyes large but not prominent laterally, their upper part 

 being capable of complete retraction within the prothorax. 

 The buccal organs are greatly reduced and without biting 

 parts. The labrum is exserted but very small and fleshy, 

 the mandibles are without teeth, the tips blunt and pro- 

 duced forward, the inner edge membranous, and the 

 maxillae are without a lower lobe, long and fleshy. The 

 last joint of the palpus is longer than the other two 

 together. The mentura is small and semicircular without 

 a distinct ligula. The last joint of the labial palpus is 

 long, the others small. The antennae are small and 

 10-jointed, the outer lamellse of the 3-jointed club being 

 slightly cup-shaped. 



The body is short, stout and thickly clothed beneath 

 with long tawny hairs. The front coxae are very promi- 

 nent, the middle discoidal, the hind stout, with a narrow 

 transverse stridulating file near the outer end. The femora 

 are stout, the anterior tibioe tridentate, with a very long 

 spine, which is strongly spatulate in the male, and the 

 four posterior tibise very strongly conically expanded at 

 their extremities, each armed with two long terminal 

 spines. The tarsi are slender. The abdomen is much 

 reduced and almost entirely covered by the elytra, and 

 consists ventrally of six visible segments. 



