146 
prolonged into an ovipositor in the female ; it varies so much in 
form in the two sexes, especially as to the outline of the apices 
of the ventral and dorsal plates, that it affords no constant cha- 
racters for the formation of groups within the genus. The males 
are larger and more robust than the females, the anterior legs 
also being longer and stouter, and having dilated and fringed 
tarsi. In these typical forms the body is somewhat depressed 
above, with a very gradual and slight slope posteriorly ; with this 
the elytra are narrowed nearly in a uniform degree from base to 
apex, and the thorax is widest at its hind angles, with a gradual 
attenuation from its base to its apex. 
These characters, however, do not hold together so as to form 
a well-defined genus. Some species, which in all other respects 
are true ColohotliecB^ recede from the typical forms in the shape 
of the thorax. Thus C. Schmidtii has a thorax approximating 
to that of some members of the Leiopodine group, having a 
lateral tubercle towards the hind angles j and C. lineola presents 
a thorax of nearly the same form as (EdopezUy Trypanidius, and 
the allied genera. The dilatation of the male tarsi also fades 
away from species to species, and some of these aberrant forms 
have the elytra less depressed and more narrowed near their 
apices than in the more typical ColohothecE. Notwithstanding 
this diversity, I have failed in my attempts to divide the genus. 
One of the aberrant forms constitutes the genus Priscilla of 
Thomson (Systema Ceramb. p. 30). It is much less elongate 
and more convex than the true Colohothecc, and the shoulders of 
the elytra form a larger and more elevated ridge; I have not 
ventured, however, to separate it from the rest whilst many 
other species equally entitled to form distinct genera remain in 
the genus. 
§ L Fore tarsi not more dilated in the male than in the female. Thorax 
narrowed at the base, and tumid or tuberculated behind the middle on 
each side. 
I. Colohothea lignicolor. 
C. modice elongata, brunnea cinereo nigroque variegata, corticis 
fragmentum simulans ; elytris apices versus subito attenuatis, 
apicibus minus late sinuato-truncatis utrinque bispinosis, dorso 
costatis. Long. 6 lin. $ . 
Head clothed with tawny-brown pile. Antennae twice the 
length of the body (2)j brown, bases of the joints pale ashy, 
basal joint ringed with ashy. Thorax widened from the front to the 
lateral tubercles, which are short and acute, then strongly atte- 
nuated and incurved to the base ; surface convex, varied with light 
and dark brown, and with two black vittae each interrupted in 
the middle ; side, below the tubercle, black, shiny. Elytra short 
