36 CALIFORNIA ACADEMY OF SCIENCES. 



biiim, being absent in the latter genus. In Hesperobkim 

 ccdifornicnm they are very large, slightly oval, strongly an- 

 nular and crater-like, occupying the entire summits of slight 

 elevations, and having their planes not exactly parallel to 

 the general surface but tilted very slightly forward, so that 

 the slope of the elevation is more prominent behind. Be- 

 tween them the surface is narrowly elevated or tumid in a 

 longitudinal direction, and from the middle of each arises a 

 very long erect seta from an annular median tubercle, which 

 corresponds to the cone of the crater. These most singular 

 structures are probably an additional distinctive feature of 

 Hes23erobium. 



The genus Homseotarsus founded by Hochuth upon an 

 Armenian species, does not concern us at the present time, 

 as, although the maxillary palpi are apparently of like struc- 

 ture, it is, in almost all other respects, entirely similar to 

 Cryptobium (Lac. Gen. Col. 11, p. 90). 



II. 



In the first volume of this Bulletin, page 315, 1 stated that 

 the mandibles in Or us were qiiadridentate within. This is 

 true only of the riglit mandible. Since the publication of the 

 paper referred to, I have examined the left mandible and 

 find it tridentate, the three teeth being small, approximate 

 and situated almost exactly in the middle of the inner margin; 

 the two basal ones are erect, slightly longer than wide, acute 

 and equal, the third being longer and more slender, acute 

 and rather strongly inclined toward the apex, the latter 

 being evenly and strongly arcuate, very acute and slender. 

 This combination of four teeth in the right and three in the 

 left mandible is of frequent occurrence in the portion of the 

 Psederini near and related to Lithocharis, where the man- 

 dibular characters appear to lose the importance wdiich they 

 possess in some other portions of the i;roup. Tlie abnormal 

 arrangement of the teeth in Orus therefore, although it cannot 

 of itself be maintained as a generic character, still serves to 



