BIOLOGICAL PAPERS. 287 



terior margin of the clypeus impunctuate; scape rather clavate, pedicellum 

 shorter than wide, first joint of the flagellum a little longer than the second joint, 

 nearly as long as the scape. Antenna? twenty-six jointed. Thorax dull, except 

 the metanotum, which is rather shining; mesonotum irregularly reticulate, 

 pleura regularly, distinctly reticulate, mesonotum with coarse longitudinal striai 

 on the superior face and diverging stria? on the posterior face, the surface be- 

 tween the etriai uneven, lateral spines blunt, prominent, diverging; neuration 

 characteristic, the second abciesa of the radius straight, forming an obtuse angle 

 with the first abcissa ; membrane hyaline, costal nervure pale brown, median, 

 submedian and basal nervures testaceous, other nervures and stigma dark brown. 

 Abdomen dull, reticulate, but more moderately than the pleura; basal third of 

 the abdomen with two raised lines that diverge basally and are obsolescent an- 

 terior to the basal third of the segment. Uniformly sericeous, the pubescence 

 short and in no place hiding the tegument. Black: anterior femora testaceous, 

 tinted with ferruginous; middle femora ferruginous, black at base; anterior 

 tibiie and tarsi dull testaceous, somewhat infuscated, terminal joints blackish; 

 po3terior femora ferruginous, tibia? yellow and ferruginous, fuscous at base and 

 apex, posterior tarsi at base and spurs pale yellow, apex: of metatarsus and suc- 

 ceeding tarsal joints blackish; abcjomen black at base, beyond the black are two 

 testaceous spots separated by a ferruginous broad line which is continuous with 

 the ferruginous color of the remaining portion of the abdomen ; abdomen at apex 

 somewhat infuscated. 



Type: University of Kansas. Type locality : Bill Williams Fork, Ariz. One 

 specimen. August, 1903, F. H. Snow. 



Chelonus nucleolus, n. sp. 



Female. — Length, 4 mm. Head dull, minutely, rugulosely sculptured; 

 clypeus as in the preceding species. Antenna^ broken. Thorax dull; mesonotum 

 partly obscurely reticulate, partly somewhat shining, rather smooth and minutely 

 sculptured; scutellum, pleura and metathorax reticulated, the latter somewhat 

 shining; the metanotum has two longitudinal ridges rather widely separated, 

 the space between about one half as great as the space to each side; wings as in 

 the preceding species, the dark nervures and stigma paler. Sericeous as in the 

 preceding species. Abdomen finely rugulose and somewhat striate on basal third, 

 the diverging raised lines on the basal third indistinct. Black; mandibles cas- 

 taneous except at apex and base ; trochanters pale and dark brown ; tibia? of 

 anterior legs pale brown, yellowish, dark brown on basal half; middle tibia? uni- 

 formly yellowish, tinted with brown; posterior tibia? dark brown at base and on 

 greater part of apical half yellowish, between tarsal joints yellowish tinted with 

 brown, apical joints fuscous : basal third of abdomen with a clearly defined broad 

 testaceous band, extreme base of abdomen dark brown. 



Type: University of Kansas. Type locality: Oak creek canyon, Arizona. 

 One specimen. August, 1902, F. H. Snow. 



Chelonus exogyrus, n. sp. 



Female. — Length, 4 mm. Head dull, rugulose, reticulate; cheeks rather 

 shining and striate; clypeus as in the preceding species; scape a little longer 

 than the first joint of the flagellum, pedicellum wider than long. Antennse 

 twenty-six jointed. Thorax dull, rather coarsely reticulate; pleura somewhat 

 shining; metanotum with two longitudinally arranged, oblong, rough, shining 

 spaces bounded by salient raised lines, posterior face of metanotum with radiating 

 ridges that are obsolete near the apical edge; lateral spines as in the preceding 

 species; wings as in 653. (?) Abdomen dull, delicately rugulose and reticulate; 

 basal half rather striate, basal raised lines not distinct, diverging as usual. 



