lyiH.] F. H. (Ikavklv: PassaUdae of the World. 89 



J 



'' The tips of all six lamellae forminj; a strai^'ht line when the 

 antenna is furled ; the anterior niarfiinal depressions of the 

 mentuin always large and separate ; the sides of the elytra 

 hairless .. .. .. •• .. 0. siugajjurae, p. 87 . 



lie tips of the (irst twn lamellae not fallini; i" line witli those 



I of the other four when the antenna is furled ; the anterior 

 mar-iinal depressions of the mentum very variable, often fused 

 or nidimentarv : the sides of the elytra densely hairy in front 0. wallnrci, p. ><7. 

 < The anterior maruinal depressions of the mentum very larjie ; 

 \ the sides of the elytra hairless . . . . . . 0. inaeqiiaUs, p. 87. 



'"^1 The anterior marginal depressions of the mentum more or less 

 ( nulimentary ; the sides of the elytra hairs- . . . . . • . . G- 



C The upper tooth of both mandibles well developed, more or 

 ) less rectangidar ; the frontal area markedly transverse . . 0. aequnlis, p. 88. 

 ^1 The upper tooth of both mandibles nulimentary or at least 

 ( more obtuse : the frontal area about as long as broad . . . . . • « • 



The anterior lower tooth of the left mandible very large, much 



larger than that of the right mandible . . . . ■ • ■ • 8. 



The anterior lower tooth of the left mandible .scarcely larger 

 than that of the right . . . . • . ■ ■ 0. aequuhns, p. 88. 



The upper tooth of the left mandible obtuse but moderately 

 ^ lart'e ; the seventh ribs of the elytra almost unpunctured . . 0. jaiensis, p. 88. 

 ^) The upper tooth of the left mandible minute ; the seventh ribs of 

 / the elytra sparsely pimctured and hairy throughout . . 0. minor (Gravely). 



Genus ACERAIUS, Kaiip, iS68ci, pp. 26-27. 



Type, Passahis grandis, Burmeister. 1S47. p. 463. 



Acera us lamellatus n. sp. 



:\Ir. Holinan-lluiit has submitted two specimens from the Malay Peninsula (Uhi 

 (Jombak), and Mr. Brvaut two from Penang. one of each of which has been presented to the 

 Indian Museum collection. Length 23 mm. 



This species appears to be allied to various species of the genus Ophri/gonius on the one 

 hand, and to the genus Accra ins on the other. The antennal lamellae and mentum resemble 

 those of Ophrmionius simjapiirac, the former being exceptionally large for so small an 

 insect. The mandibles are of the Aceraixs type, and resemble those of A. helfcri except that 

 the convexity of the posterior part of the upper margin is pres.sed further back from the small 

 upper tooth. In other respects this species resembles Ophri/iionius minor, except that the 

 eighth ribs of the elvtra are punctured instead of (or as well as) the seventh. 



Aceraius helferi, Kuwert 



PI. 1. 



Aceraim helferi. Kuwert. 1898, pp. 340-347. 



Acerniu/t helferi + Im-niiniiii.^ + ai^samensis + him'tlnif^nsi.^, (Jravely, 111 lie. pp. •j:il)--23S, pi. .\u. 



figs. 3(;-30(i. 



One specimen from Burma and four from Siam. three of the latter lieiii^ fic.in Renong. 



M. Vitalis de Salvaza has presented a tine seiies of this species fn.m Tonkin (Chapa 



and Xieug Khouang). and has sent for examination specimens from Ban Tink and Lao 



N 



