Bees from New Mexico, U.S.A. 65 
The first abdominal segment is often more or less covered 
- by brown mites. 
, 
(4) Halictus subobscurus, sp. n. 
@. Length about 6 millim.; black, pubescence whitish, 
sparse. Head moderately broad ; face beiow antenne more or 
less covered with short white hairs (but not densely snow- 
white pubescent, as in some species), vertex minutely 
roughened. Antenne brownish towards tips. Mesothorax 
quite dull, parapsidal grooves not apparent. 
Postscutellum with pale pubescence. Enclosed portion of 
metathorax rounded behind, not truncate; its margin not 
indicated by a sharp elevated ridge, but by a rounded raised 
portion free from hairs; its surface anteriorly rather feebly 
longitudinally wrinkled. Sides of metathorax hairy ; 
descending hind end of metathorax with a group of about 16 
well-separated very distinctly plumose hairs on each side of 
the middle. 
Tegule testaceous. Wings hyaline, nervures and stigma 
dull yellowish brown. Third submarginal narrowing rather 
less than half to marginal. Legs with short hairs; tarsi 
fulvous. 
Abdomen fairly shiny, very minutely and closely punctate ; 
not fasciate, but apical margins of segments obscurely testa- 
ceous (not distinctly so, giving the appearance of bands, as 
in some species). Ventral segments with bands of hairs, 
only conspicuous when viewed sideways. 
Hab. On Sisymbrium canescens, College Farm, Mesilla 
Valley, N.M., April 12, 1895 (Ckll. 2689). 
The following table has been prepared to distinguish 
several species more or less similar to swbobscurus :— 
Mesothorax very shiny; median and _ lateral 
grooves distinct; stigma dark; abdomen ’ 
with four lateral patches of white hairs.... pectoraloides, Cll, 
Mesothorax not so shiny. 
Stigma dark; abdomen with four more or less 
defined lateral patches of white hairs. 
Head decidedly longer than broad ; meso- 
thorax with larger punctures; meta- é' 
thorax more coarsely sculptured ...... pectoralis, Sm. 
Head nearly round; mesothorax with smaller 
punctures; metathorax more finely t 
BMPR E ML hea eie, «Ais, elas a eh~) ato eiale Wai om a) Phake quadrimaculatus, Rob. 
(pectoraloides has the shape of head intermediate between these two.) 
Stigma yellowish. 
Headtlarge and broad... esc eee as we arcuatus, Rob. 
Head small, moderately broad............ subobscurus, Ckll. 
Head comparatiyely narrow..........+++. gracilis, Rob. 
Ann. & Mag. N. Hist. Ser. 6. Vol. xvi. 5 
