Royal Physical Society. 159 



a f Margins of thorax paler than middle . . angustatus. 



I Margins of thorax not paler than middle ... do. var. cisteloides. 



f Base of thorax cut in, so as not to form a continuous 



r I outline with elytra 6 



' J Base of thorax forming a continuous outline with 

 I elytra or nearly so 19 



{^Colour of pubescence grey and brown or dull yellow 

 on thorax, yellowish hairs on base and margins 

 of elytra wanting or scarcely perceptible, and 

 6.«{ either no bloom or grey bloom on elytra 7 



I Colour of pubescence clear yellow on thorax, a 

 brownish-blue or purplish bloom on the elytra, 



L and yellowish hairs on base and sides of elytra... 14 



{Antennae longish and subfiliform, not heavily 

 clubbed 8 

 Antennas shorter and more clavate 12 



£ f Elytra transversely strigose acicularis. 



' \ Elytra not transversely strigose 9 



q f Antennae with apex pale picipes. 



' \ Antennae with apex not paler than rest 10 



« J Posterior angles of thorax acuminate behind 11 



' \ Posterior angles of thorax not acuminate behind... fuscus*. 



{Posterior angles much produced, antennae wholly 

 ferruginous meridionalis. 

 Posterior angles only slightly produced, antennae 

 more dusky towards apex nigricans. 



o f Antenn ae very heavily clavate chrysomeloides . 



'\ Antennae only moderately clavate 13 



o J Insect thin and narrow morio. 



' \ Insect shorter and more compact cor acinus. 



j /Antennae comparatively long and subclavate nigrita. 



' X Antennae heavily clavate 15 



{Thorax deeply punctured neglectus. 

 Thorax more or less transversely granulose or 

 wrinkled 16 



,. J Thorax nearly parallel on the sides quadraticollis . 



L ' X Thorax not parallel on the sides 17 



m J Thorax faintly transversely wrinkled 18 



* X Thorax granulose tristis, var. rotundicollis. 



Thorax short, transverse, and not broad; elytra 



usually very long tristis (type). 



Thorax broad, elytra moderate in length ... tristis, var. grandicolli 



* Fuscus is one of those species, which, from their transitional charac- 

 ers, nearly put dichotomy at defiance. It might almost be placed under 

 No. 19 instead of No. 6, as the base of the thorax has only a slight inter- 

 ruption in its continuity ; and again, its brown or purplish elytra are not 

 unlikely to induce one to place it under No. 14 instead of No. 7» 



