554 



PSYCHE. 



November 1893. 



the nearest eye-margin; antennae shorter 

 than in the $, joints 1-6 of the flagellum 

 produced into a strong angle or tooth 

 beneath, joints 1-4 much narrowed basally; 

 from joint six the flagellum gradually tapers 

 to the apex; apical portion of abdomen 

 blackish ; last ventral segment of abdomen 

 roundly emarginate at apex. Length 7 mm. 

 Nevada (Morrison). Four specimens. 



Plenoculus gen. nov. 



Eyes within not emarginate, distinctly con : 

 verging towards the clypeus ; the ocelli round 

 and prominent; antennae short and stout, 

 originating immediately behind the clypeus; 

 head transverse, wider than the thorax ; outer 

 edge of mandibles strongly emarginate; palpi 

 rather prominent, the maxillary palpi 6- 

 jointed, the labial palpi 4-jointed; in the $ 

 the clypeus has on each extreme side a fringe 

 of hairs as in Cerceris; pronotum lower than 

 the level of the dorsulum ; metathorax dis- 

 tinctly shorter than the dorsulum ; legs stout, 

 the femora narrower at apex than at the 

 base; four hind tibiae and tarsi strongly 

 armed with spines, those on the anterior 

 tarsi forming a weak comb; tibial spurs 

 large and strong, the hind tibiae two-spurred, 

 the others with but one spur; tarsal claws 

 long and slender, not toothed, in the $ 

 much smaller ; marginal cell at apex obliquely 

 truncate, with a distinct appendiculation ; 

 three submarginals, of which the first is 

 nearly twice as long as the other two com- 

 bined, the second petiolate, the third is 

 oblique and is slightly narrowed above, the 

 first recurrent nervure received by the first 

 submarginal cell near its apex, the second by 

 the second submarginal cell between its 

 middle and apex, the discoidal and basal 

 nervure meet at a short distance from the 

 apex of the submedian cell, this cell being 

 therefore shorter than the median cell on 

 the externo-medial nervure; stigma small, 

 scarcely distinguishable from the costal 

 nervure; abdomen shaped as in Oxybelus: 

 last dorsal segment $ with a distinct 

 pygidial area. 



This genus seems to be most closely re- 

 lated to Tachyrhostus Saussure from Aus- 

 tralia; it is, however, different in the fact 

 that it is not at all metallic in coior, the head 

 being broader than the thorax, the wide 

 emargination of the mandibles, the narrow 

 vertex. From Bothyiiostethus. it is distinct 

 by the eyes converging towards the vertex, 

 the marginal cell with an appendiculation, 

 and the hind femora being not broadened at 

 the apex, etc. 



It may be that this is the genus described by 

 Patton, from New York,* but his description, 

 "Second submarginal cell petiolate," is of no 

 value as some half a dozen genera of the 

 Larridae possess that character. Pleno- 

 culus is also distinguished from Sylaon and 

 Solierella in possessing a pygidial area and 

 by the legs being strongly armed. 



Pleuocultts davisi. $. — Anterior margin 

 of clypeus deeply incised, armed with 

 five teeth on each side, the outer and inner 

 tooth is generally the largest, the others 

 being in some specimens indistinct; front 

 very finely granulated, with a long, distinct, 

 medial impressed line, which originates in a 

 strong fovea, before the anterior ocellus and 

 extends down between the base of the 

 antennae; ocelli forming a triangle; on each 

 side of anterior portion of vertex there is a 

 curved furrow, running from each hind 

 ocellus to the inner eye-margin ; first joint of 

 flagellum possibly a little shorter than either 

 the second or third, which are a little longer 

 than any of the following joints, except the 

 last; dorsulum and scutellum with very fine, 

 close punctures, both strongly convex; suture 

 between dorsulum and scutellum strong; 

 metathorax above very finely granulated, 

 rather strongly furrowed down the middle, 

 the extreme base generally with a transverse 

 series of small fossae, sides and posterior face 

 very finely striated; abdomen finely and 

 closely punctured, the pygidial area triangu- 

 lar, with large, sparse punctures, its lateral 

 ridges not well defined; black; clypeus, 



* Kntomological news, iii, p. 90. 



