5. ODONTOMYIA 137 



seo-ments. It has no close ally in Europe, though 0. argentata is about 

 the same size and shape but is easily distinguished by its glistening 

 abdomen, longer basal antennal joint, unforked cubital vein, and bare eyes 



of the male. 



0. tigrina is not very uncommon in Britain though T have very seldom 

 seen it alive. It occurs about ponds and in marshes, and I have records 

 from Hampshire (Fawley and Fordingbridge), Sussex (Lewes and Bognor), 

 Kent (Lewisham, Gravesend), Suffolk (Tostock and Drinkstone), and 

 Hereford (Ledbury), while Colonel Yerbury has taken it at Aviemore in 

 Inverness. The dates extend from May 14 to July 12. It is recorded 

 from all Europe north of the Alps except in the extreme North. 



Synonymy. —hi the Hope Museum at Oxford a pair of this species and a male of 

 0. argentata hove a printed label " 0. atrata" but I cannot trace where the name 

 came from. 



3. O. angulata Panzer. Abdomen with a broad dentate greenish 

 margin which leaves trapezoid black markings on the disc ; the two basal 

 trapezoid markings equal in size, and widest against the foremargins of the 

 segments but not band-Hke there. Antennte tawny except at the tip. 

 Legs all orange. 



A medium-sized species, distinguished by the shape of the 

 abdominal markings. 



S. Head large, distinctly broader than the thorax. Face black, rather shining 

 but obscured by abundant yellow pubescence, and with an orange brown 

 middle line which extends from the small facial knob down to the mouth, 

 and with all the mouthmargin rather widely orange brown ; jowls orange ; the 

 mouth-opening extends in front fully half-way up the face leaving the black 

 sides of the face on the upper part a little puffed out. and when viewed side- 

 ways the face just below the antennae projects a little into a slight knob 

 which in conjunction with the puffed-out black sides of the face slopes down- 

 wards from the sides of the upper mouthmargin ; the mouthmargin is bare, 

 but the pubescence of the face is continued as a conspicuous rather long fringe 

 all round the inner and lower margin of the eyes, extending outwards again 

 on to the jowls ; back of the head shallow below but deeply hollowed out 

 above, and apparently bare ; vertex slightly raised, shining black, extending 

 forwards to a very long narrow point on all of which there is short brownish 

 orange pubescence ; frons very small, moderately shining black, with two 

 small tufts of short yellow pubescence on the upper part. Eyes bare, touch- 

 ing for only a short space near the frons ; small facets on the lower part 

 sharply distinguished from the larger facets on more than the upper half. 

 Antennae obliquely porrect, practically touching at the base, little more than 

 half the length of the head, and deep orange from the base up to the blackish 

 last annulation of the flagellum ; two basal joints thin and about equal in 

 length; third joint thin, nearly three times as long as the second and 

 cornposed of four nearly equal annulations, besides the brownish red style, 

 which is scarcely more than a third the length of the flagellum and which has 

 a short orbicular basal joint. 



Thorax black with a slight aeneous tinge and with universal greyish 

 yellow pubescence, which is shortish on the disc but longer and conspicuous 

 about the sides and on the pleurae ; pubescence all composed of soft fairly 

 erect hairs. Scutellum black with a broad orange margin and with two 

 brownish orange marginal spines of which the tips are blackish ; pubescence 

 short and inconspicuous, greyish yellow, and not specially marginal. 



Abdomen shining black, slightly dulled by minute but coarse punctuation 



