288 GEO. H. HORN, M. D. 



ment (fig. 19) flattened at middle and rugosely punctured. Last 

 ventral segment with a dentiform process, prolonged backward from 

 the anterior margin and bifid at its tip. 



Female. — Antennal club nearly as long as the funiculus. Py- 

 gidium longer than in the male. Posterior tarsi very little shorter. 



Variations.— Scarcely any variation has been observed, except 

 in size. One specimen from southeastern California is brownish, but 

 this is probably from bad preservation. 



This species resembles some of the larger forms of tristis, but is 

 distinctly less hairy. These two species are remarkable in the fact 

 that the sides of the clypeus do not extend over the eye to form the 

 canthus, so that Avhen viewed directly from above the clypeus seems 

 acutely notched immediately in front of the eye. This character is 

 even better marked in this species than in tristis. 



Among the numerous specimens examined there is a variation in 

 the number of the joints of the antennae. AVhile the normal num- 

 ber is ten joints some have one antenna with nine only, and in sev- 

 eral specimens it is not possible to determine with certainty how 

 many joints there are between the scape and club. 



Females seem to be rare, as there is but one of that sex in seven- 

 teen specimens. 



Occurs in Arizona (Morrison) and southeastern California, 



Group XVII, heterodoxa. 



Form oblong-oval, surface shining, without hairs. Clypeus sub- 

 truncate, concave, margin rather widely reflexed. Last joint of 

 maxillary palpi fusiform, not impressed. Antennae lO-jointed. Mar- 

 gin of thorax slightly irregular. Anterior tibise normally tridentate. 

 Posterior tibiae with both spurs free in the two sexes. Claws unlike 

 in the two sexes, and in the male dissimilar on various tarsi. 



For reasons already given I ])refer to retain this species as an 

 aberrant Lachuosterna rather than separate it with a new generic 

 name. 



The claws of the anterior tarsi S as represented in fig. 44 have a 

 rather broad basal dilatation, the tooth, not projecting beyond it, of 

 broadly triangular form, the apical portion of the claw curving down 

 close to the tooth. The inner claw of the middle tarsus is like the 

 front claw. The outer middle claw is very different. The tooth is 

 very large and deflected to one side so that the claw is almost bifid, 



