CERAMBYCIDAE. 317 



Additional cliaracters are: eyes rather finely granulated, small, 

 deeply emarginate; front coxal cavities rounded, closed behind; 

 middle coxal cavities angulated externally but closed ; ungues 

 divaricate, last tarsal joint less elongated than in Durcadiini. 

 Intercoxal process of 1st ventral segment wide. 



Mr. James Thomson has established Oraoscylon on M. sub- 

 rugosum Bland, a species of Lower California in which the pro- 

 thorax has no lateral spine. The distinction is illusive, as all 

 gradations in the degree of development of the spine are seen, 

 from M. armatum where it is large and acute to M. annxdatum 

 Say, where it is obtuse, and finally to 31. ajjpressmyi Lee, and 

 subi'ugosuin, where it is wanting. 



Tribe III.— MICHTHYSOIWIIVI. 



This tribe has been established on the very anomalous Mich- 

 thysnma heterodoxum Lee, of which a single specimen has been 

 found in the upper part of Georgia. The head is rather large, 

 the front short, scarcely vertical, the support of labrum visible, 

 coriaceous, labrum small, rounded in front. Palpi very unequal, 

 with the last joint securiform. Antennaj slender, as long as the 

 body, scape rather stout, as long as the 3d joint, rounded at tip, 

 without cicatrix.; 3d joint not longer than 4th ; eyes small elon- 

 gate, coarsely granulated, lower lobe narrow. Prothorax as wide 

 as the head, with an acute lateral spine, rather in front of the 

 middle. Elytra elongate not wider than prothorax. Interc(jxal 

 process of first ventral segment acute. 



Front coxal cavities angulated, closed behind ; middle ones 

 angulated, closed externally; thighs strongly clavate, front tibite 

 curved inwards and feebly sulcate, middle ones absolutely without 

 tubercle, sinus, or tuft of hair on the outer margin ; tarsi Uiss 

 dilated than usual, 1st joint of hind pair equal to two following- 

 united ; last joint moderate, claws divaricate. 



The form of the palpi seems to show an affinity with the 

 African genus Phantasis, but the body is niuch more elongate, 

 and the other characters do not agree. The head and prothorax 

 are densely punctured and opaque, the elytra more shining, less 

 densely punctured, with hairs proceeding from the punctures. 



