new Coleoptera from Madagascar. 289 



PRIONIDiE. 

 Hoplideres nigicoUis, n. sp. 



Elongates, parallelus, piceo-niger ; capite thoraceqiie crebre 

 fortiter rugosis, his lateribus acute quadrispinosis ; scutello 

 siibtilius ruguloso-pnnctato ; elytris parum nitidis, fere parallelis, 

 circa scutellum nitidis j^arcius punctatis, humeris acute spinosis, 

 ? . Long. 21 lin., lat. 8 lin. 



Very close to H. spinicoUis, from wliicli it differs in having 

 the elytra more parallel, not expanded at the sides, and the head 

 (especially round the eyes) and thorax are decidedly more 

 rugose ; the spines also on the sides of the thorax are more 

 slender. 



CERAMBYCID^E. 



Arrhythmus, n. gen. 



General form somewhat that of EUginoderma. Head very 

 similar to that of that genus, biit with the antennal tubercles 

 more flattened and not divided in the middle, with only a very 

 slight spine at the vertex. Antennas about ^ longer than the 

 Avhole insect, slender, particularly towards the apex, slightly 

 pubescent below. Thorax sub-cylindrical. Elytra rather flat 

 above, at their base twice as broad as the base of the thorax, 

 distinctly constricted a little before the apex, which, in con- 

 sequence, appears somewhat expanded. Femora very much 

 enlarged at the apex, compressed ; tibite compressed. Abdomen 

 narrowed towards the apex. 



The position of this rather singular insect is somewhat doubt- 

 ful, but after a careful examination I am of opinion that it 

 should be placed at the end of the Eligmodermina' . The 

 antennal tubercles are not, however, divided as they are in that 

 group, and in this respect it ap^^roaches more to the Callidiopsin(e, 

 l)ut in all other characters it accords lietter with the former. 



Arrliythnns rugosipennis, n. sp. 



Elongatus, nitidus, niger, antennis articulis 4-11 plu- 

 minnsve flavescentibus ; capite thoraceque tenuissime griseos 

 pubescentibus ; elytris crebre fortiter punctatis, dimidio apicali 

 anguste flavo-marginato, disco maculis duabus rotundatis flavis ; 

 pedibus flavis, femoribus apice nigris, $ . Long. 9 lin. 



