5. ODONTOMYIA 139 



on the pleurae the pubescence is longer and more erect ; humeri, postalar 

 calli, back part of mesopleuras, broad spaces round the front cox£e, and an 

 oblique strijDe on the hypopleurae, luteous. 8cutellum more shining and 

 with more sparse less adherent pubescence, 

 and the pubescence on the under side longer ; 

 the luteous margin is so wide as to leave only 

 a shallow arched black base. 



Abdomen (fig. 131) more shining black be- 

 cause the punctuation is less coarse though 

 just as dense ; the broad green margin is so 

 broad from the base to the end of the fourth 

 segment that the black dorsal spots on the 

 second, third, and fourth segments are almost 

 exactly equal, each occupying just half the 

 foremargin and more than a third of the hind- 

 margin with the sides not absolutely straight ; 

 the fifth segment is more extensively black 

 but has the hind part irregularly and rather 

 obscurely green, and has the middle of its 

 hindmargin orange, which unites with the 

 orange of almost all the sixth segment. Belly 

 all yellowish green with universal very short 

 pale pubescence Ovipositor with the basal y.a.izi.-odoatomyiaanciuiata ^. 

 plate blackish, followed by tour orange lamellae. x 8. 



Wings with the cubital fork just beyond the 

 middle of the submarginal cell Squamae yellow, with the margin faint but 

 just obvious. Halteres with an apple green knob. 



Length about 9 mm. 



This species probably varies considerably, but the description is given 

 in detail from one male (probably British) in the Hope Museum at Oxford 

 and from one female taken by myself at Tuddenham near Barton Mills 

 in Suffolk. I have not ventured to give any details from continental 

 specimens, as it is very desirable to know first the limits of our British 

 form. Of the recognised allied species, 0. hydrolcon has the antennte 

 usually all blackish, and the face of the male all black and of the female 

 marked with black, while Schiner especially notes the band -like widening 

 of the front part of the abdominal black dorsal spots, but as he says the 

 eyes of the male are hairy I am compelled to doubt his identification of 

 the species ; 0. hyclropota has the second abdominal black dorsal spot 

 smaller than the first and widest at the middle of the segment instead of 

 at the foremargin ; 0. liydroi^hila only occurs in extreme South-east Europe 

 and Sicily, so is not likely to occur with us; 0. felina has the green 

 abdominal margin very narrow. 



0. angulata became known to me as British from a female which I 

 raught at Tuddenham near here on July 20, 1880, and I think I have 

 since seen (but missed) a specimen at Chippenham Fen. Mr H. W. 

 Andrews took three females at Sutton Broad in Norfolk on July 14, 1905, 

 which are very similar to the specimen I have described, but all the green 

 markings have become very orange and the specimens are slightly smaller. 

 I expect that under favorable circumstances it is not uncommon in the 

 Fens or Broads in July or August; there are a few specimens in the 

 Dalean collection at Oxford under the names of 0. hydroleon and 0. 

 hlldropota, and in the old British collection of the British Museum under 

 the name of 0. felina, and in the Entomological Club collection. A male 

 in the Dalean collection (with an undecipherable label beginning 

 apparently "Cosm") has rather small green spots on the sides of the 



