178 GEO. n. HORN, M. D. 



0. xparsus, Lee. — Mentuiu broader than long, not narrowed in from, 

 anterior angles rounded, surfiice plane, not impressed, apex arcuate. 



0. sfriatus, Lee. — Mentum broader than long, feebly narrowed in 

 front, tip not eniarginate, a transverse arcuate line of rather long 

 bristly hairs, causing the mentum at first sight to appear very short, 

 broadly eniarginate and serrulate in front. 



These variations of the form of the mentum have given me the 

 basis of the synoptic table. Other characters however require special 

 mention. 



In all the species with one exception the prosternum is very short 

 and truncate or broadly rounded, while in pectoralis the prosternum 

 is produced into a lobe imitating in a diminished form that of 

 Ilololepta. 



When the head is thoroughly deflexed, the globular eyes are re- 

 ceived in fossa; at the angles of the thorax beneath. The antennse in 

 repose pass beneath the eyes, the clubs become approximated and are 

 received into fossae situated immediately in front of the anterior coxae 

 on each side of the short prosternum. These fossae are more or less 

 approximated, in pectoralis separated by a narrow carina, which in the 

 other species becomes gradually broader as they stand in the table, 

 (biarniatus should however be next to pectoralis in this respect), until 

 in sparsus the carina is broad and flat. 



The spur of the anterior tibia is moderately long and stout and in 

 well preserved specimens bears on each side a row of moderately long 

 ^^^^ bristles. The spurs of the middle tibi:« are dissimilar, the 

 S^^9 outer is slender, the inner broader, slightly curved and pecti- 

 ■nltlH "^'^ along its inner margin. This character, of extremely 

 l^ji^l rare occurrence in Coleoptera, appears to have been entirely 

 ^^^^ overlooked by those who have described Ochodxus ; it is 

 very distinctly marked in the Siberian ferrugineus. The posterior 

 spurs present nothing peculiar, they are slender and long. 



The first hind tarsal joint is always long but in pectoralis it is very 

 long and stout, arcuate, longer than all the other joints toijether and 

 longer than either spur. This species has the hind tibia? more slender 

 and longer than usual. 



The sutural angle of the elytra is obtuse or rounded, excepting in 

 pectoralis and biarmatns. In these the tip is sinuate before the suture, 

 and the angle very distinctly {pectoralis} or obtusely (Jnarmatus) 

 dentiform. 



Certain modifications of the propygidium are worthy of notice. 

 The posterior margin is always very slightly reflexed especially at its 



