50. ASILUS DETERMINATUS, n. s. _Mas et Foem._ Cinereo-niger, capite
subaurato, antennis nigris, thorace vittis tribus cinereis, pedibus
fulvis robustis, femoribus nigro vittatis, tibiis apice tarsisque
nigris, alis fuscis, halteribus testaceis. _Mas._ Abdomine pilis
basalibus luteis. _Foem._ Abdomine pilis basalibus cinereis dimidio
apicali stylato.
_Male and Female._ Cinereous black; head slightly gilded in front,
with pale hairs beneath; epistoma not prominent; mystax with many
pale, and above with a few black bristles; antennæ black; third joint
lanceolate; arista nearly as long as all the preceding joints; thorax
with three cinereous stripes, the lateral pair dilated towards the
humerus on each side; pectus cinereous; legs tawny, stout; femora
striped above with black; tarsi and tips of the tibiæ black; wings
brown; veins black; halteres testaceous. _Male._ Abdomen with luteous
hairs towards the base. _Female._ Abdomen with cinereous hairs
towards the base; nearly half the apical part stylate. Length of the
body 10-12 lines; of the wings 18-20 lines.
51. ASILUS INTRODUCENS, n. s. _Foem._ Cinereo-niger, capite aurato,
antennis nigris, thorace vittis duabus lateribusque cinereis, abdomine
fasciculis quatuor basalibus cinereis dimidio apicali stylato, pedibus
nigris robustis rufo variis, alis fuscescentibus, halteribus fulvis.
_Mas?_ Capite argenteo, abdomine fascia basali fasciculari fasciaque
subapicali albidis latis, alis obscure cinereis.
_Female._ Cinereous black; head gilded in front, with cinereous hairs
beneath; epistoma slightly prominent; mystax with several gilded
bristles, and above with a few black bristles; antennæ black; 3rd
joint lanceolate, nearly as long as the arista; thorax with two
cinereous stripes, which are dilated on each humerus; sides and pectus
cinereous; abdomen with two cinereous tufts on each side at the base;
nearly half the apical part stylate; legs black, stout; femora red
beneath and partly above; tibiæ with a broad red band; wings brownish,
somewhat paler towards the base and about the borders of the posterior
areolets; veins black; halteres tawny.
_Male?_ Head silvery in front; mystax with several white, and above
with a few black bristles; abdomen with a broad whitish tufted band
at the base, and with a broad whitish subapical band; wings dark
cinereous, partly paler, as in the female. Length of the body 8-12
lines; of the wings 12-16 lines.
52. ASILUS AREOLARIS, n. s. _Mas._ Cinereo-niger, capite aurato,
antennis nigris basi fulvis, thorace vittis tribus cinereis, abdomine
apice nigro nitente segmentis cinereo marginatis, pedibus fulvis,
tarsis posterioribus nigris, alis fuscescenti-cinereis pallido
lituratis triente basali albido, halteribus testaceis. _Foem?_
Antennarum articulo 3° fusiformi, alis fuscescentibus hyalino
lituratis.
_Male._ Cinereous black; head gilded in front, clothed with black
hairs beneath; epistoma prominent; mystax with many gilded bristles,
and above with a few black bristles; antennæ black, tawny towards the
base; thorax with three slender cinereous stripes, sides and pectus
cinereous; abdomen black and shining at the tip, hind borders of the
segments cinereous; legs tawny; posterior tarsi black; wings brownish
cinereous, with paler marks in most of the areolets, white on more
than one-third of the length from the base; veins black, tawny towards
base; halteres testaceous.
_Female?_ Epistoma less prominent; third joint of the antennæ
fusiform, hardly half the length of the arista; wings brownish;
marginal areolets with a nearly colourless spot in each. Length of the
body 10 lines; of the wings 18 lines.
53. ASILUS TENUICORNIS, n. s. _Foem._ Cinereus, capite argenteo,
antennis testaceis parvis, thorace vittis duabus fuscescentibus,
abdomine obscure cinereo segmentis testaceo marginatis, pedibus
fulvis, genubus tarsisque nigris, alis cinereis apice obscurioribus,
halteribus testaceis.
_Female._ Cinereous; head silvery white in front; epistoma very
slightly prominent; mystax with some white bristles, and above with
very few black bristles: antennæ testaceous; 3rd joint conical, much
shorter than the 1st joint, and not more than one-fourth of the
length of the arista; thorax with two brownish stripes; abdomen dark
cinereous; hind borders of the segments testaceous; legs tawny; tarsi,
except at the base and knees, black: wings cinereous, dark cinereous
towards the tips; veins black, tawny towards the base; halteres
testaceous. Length of the body 8 lines; of the wings 14 lines.
Gen. OMMATIUS, _Illiger_.
54. OMMATIUS SCITULUS, n. s. _Mas et Foem._ Fulvus, gracilis,
capite cinereo antice albo, antennis nigris basi fulvis, thoracis
disco cinereo-nigro, pectore testaceo, abdominis segmentis pallido
marginatis, alis cinereis, halteribus testaceis.
_Male and Female._ Tawny, slender; head cinereous above, white in
front; mystax with several white bristles; antennæ black, tawny
towards the base. 3rd joint lanceolate, arista not longer than the
3rd joint; disk of the thorax cinereous black; pectus testaceous;
hind borders of the abdominal segments pale; tarsi black towards the
tips; wings cinereous; veins black, tawny towards the base; halteres
testaceous. Length of the body 6-7 lines; of the wings 11-12 lines.
55. OMMATIUS STRICTUS, n. s. _Mas._ Niger, angustus capite argenteo,
pectore albido-cinereo, abdomine fusco maculis trigonis nigris,
segmentis albido marginatis, pedibus fulvis, genibus tarsisque nigris,
alis subcinereis extus nigricantibus, halteribus testaceis.
_Male._ Black, narrow; head silvery white in front; mystax with very
few white bristles; third joint of the antennæ elongate-conical;
arista a little longer than all the preceding joints together; pectus
whitish cinereous; abdomen brown, each segment with a black triangular
spot and with a whitish hind border; legs tawny; knees and tarsi
black, the latter tawny at the base; wings greyish, exterior half
blackish; veins black; halteres testaceous. Length of the body 4-4-1/2
lines; of the wings 7-8 lines.
Gen. LEPTOGASTER, _Meigen_.
56. LEPTOGASTER MUNDA, n. s. _Mas._ Cinerea, capite argenteo,
proboscide antennisque fulvis, thorace lineis duabus fuscis, abdomine
longo gracili apicem versus subdilatato, segmentorum marginibus
maculisque quatuor subapicalibus testaceis, pedibus fulvis, femoribus
tibiisque posticis nigro fasciatis, alis subcinereis, halteribus
testaceis.
_Male._ Cinereous; head silvery white; proboscis and antennæ tawny;
thorax with two brown lines; abdomen long, slender, slightly dilated
towards the tip, hind borders of the segments testaceous, two
testaceous spots on each side towards the tip; legs tawny, hind femora
and hind tibiæ with a black band on each; wings slightly greyish;
veins black, tawny at the base; halteres testaceous. Length of the
body 6 lines; of the wings 8 lines.