5. ODONTOMYIA 131 



10 (9) Abdomen with an unequal lilack dorsal stripe wliich leaves a broad 



greenish margin. 



11 (12) Abdomen with the black dorsal stripe widened band-like on the 



foremargin of the segments. Antennae blackish. hydroleon. 



12 (11) Abdomen with the black dorsal stripe unequal but not widened 



band-like (fig. 131). Antennae considerably tawny. 3 angulata. 



13 (8) Abdomen black with three pairs of large orange side-spots. 



Large species. 4 ornata. 



14 (1) Subcostal and radial veins anastomosed (fig. 127) (Hojyiodonta 



Brauer). Discal cell ordinarily with only one issuing veinlet ; 

 cubital vein not forked. Small species with a dentate greenish 

 abdominal margin. Eyes bare. 5 viridula. 



I have included 0. niicroleon, O.felina^ and 0. hydroleon in this table, because 

 they have been recorded as British under circumstances given in the list of Reputed 

 Species at the end of this volume, and they might well occur in Britain. 



8chiner says that the eyes of the male of 0. hydroleon are hairy, but they are bare 

 in the specimens in Kowarz's collection, and Lundbeck specially describes them as 

 bare. 



1. O. argentata Fabricius. Basal joint of the antennae quite twice as 

 long as the second (fig. 129). Abdomen with remarkable silvery or golden 

 shimmer, and with obscure orange side-spots. Cubital vein not forked. 



A medium-sized black species, with a silver {$) or golden 

 (?) sheen on the abdomen caused by very short depressed pale 

 pubescence. 



$. Frons and face very much puffed out and bearing dense long porrected 

 brownish grey pubescence which is very conspicuous from all points of view ; 

 the face is also very much widened and arched so that opposite the lower 

 corners of the eyes it occupies about three-quarters the width of the head ; it 

 is shining black and sometimes has a ferruginous middle line, and close 

 against each eye there is a line of much shorter glistening white hairs ; the 

 lower part of the jowls bears little pubescence but all about the large broad 

 sides and back of the mouth there is similar pubescence to that on the face but 

 hanging straight down and more brownish yellow ; close against the lower 

 front angle of the eyes is a narrow whitish shimmering band and on it is a 

 number of short glistening whitish yellow hairs, but this band does not extend 

 to the hind lower corner of the eye, l)ecause just lief ore this corner a, 

 moderately broad brownish orange eye-collar commences which extends \\\) 

 about one- third the back of the eyes and then narrows down to nothing ; the 

 lower part of the back of the head is a little inflated beyond this collar, but 

 the pubescence on and near the collar is reduced to minute brownish yellow 

 scaly hairs pointed forwards and with a silvery sheen close against the eyes ; 

 the Hat back of the head bears rather long straggly greyish pubescence ; vertex 

 shining black and bearing long brownish yellow pubescence, steadily narrowing 

 almost to the frons and the eyes never quite touching, though the inconspicuous 

 upturned brownish yellow pubescence wliich occurs on the narrowing part of the 

 vertex ceases on the short space where only the tAvo rims separate the eyes ; frons 

 black, rapidly widening out to the face, and bearing glistening whitish yellow 

 forwards flattened pubescence, and with a middle f un-ow ; proboscis long, Avith 

 large shining black sucker-flaps. Eyes bare ; facets on the upper two-thirds (or 

 three-quarters when measured round the eyes) much larger than those on the 

 lower part, and with a sharply marked dividing line almost all across the disc of 

 the eye, but on the back part the small facets extend considerably upwards 



