110 STRATIOMYID^ 



base of the lower brancli of tlie postical fork yellowish ; stigma small and 

 inconspicuously pale brownish black ; cubital fork distinct and the first sub- 

 marginal cell longer than the stigma. Squamaj (alar) black with a tinge of 

 grey in the black fringes. Halteres bright orange. 



? . Frons black with a pair of large orange spots almost on the lower half ; these 

 spots begin just where the frons bends over from the vertex, and each is of 

 elongate oval shape but extends outwards at the lower outer corner and reaches 

 the eyemargins and then extends clown against the eyes to almost the level 

 of the antennae, after which very narrow whitish eyemargins extend down the 

 sides of the black face until they widen out in a small yellow si)ot against 

 each lower eye-angle ; the black middle stripe of the frons is barely one- third 

 the width of the frons, but the yellow spots do not touch the eyes until they 

 extend outwards as mentioned above ; frons quite one-third the width of the 

 head and with almost parallel sides, and the face slightly wider, and both 

 bearing inconspicuous drooping greyish pubescence • jowls inflated and shining 

 black, but with a narrow whitish mai-gin against the eyes Avhich extends up 

 the inflated lower part of the back of the head and forms there an elongate 

 rather inconspicuous yellow spot ; rest of the back of the head inflated and 

 shining black, but with a large elongate shining orange spot on the upper half 

 of the head which does not touch the eyes, and which is narrowest below but 

 extends upwards to a level with the upper eye-angle and then slopes towards 

 the occiput, so that the black connection between the vertex and the occiput 

 is only half as wide as the space between the upper eye-angles ; pubescence 

 on the back of the head very slight and depressed ; ocellar space elevated and 

 the three ocelli obscurely yellowish. Eyes bearing fairly dense rather short 

 black pubescence. Antennae with the annulated third joint greyish ; arista 

 blackish to its tip. 



Thorax shining black with orange side-spots and two dorsal stripes ; dorsal 

 stripes extended straight to the front part but interrupted at the suture, and 

 only extended for about one-third the space after the suture (though Loew 

 says that a small spot may sometimes occur after each of them) ; the stripes 

 are rather wider apart than each is from the side-spots ; humeral knob and a 

 narrow line to the wing-base along the upper margin of the mesopleuraj 

 orange, and above these side-lines there is on each side a triangular isolated 

 orange spot above (but resting on) the suture ; postalar calli broadly orange 

 and extending triangularly to a point in the direction of the isolated spots ; 

 the narrow side-lines widen considerably near the wing-base but otherwise the 

 pleurae are black (unless the pteiopleurai are brownish). Pubescence minute, 

 stubby, and greyish black on the disc, but longer, softer, and greyish white 

 on the pleune. 



Abdomen less dulled by punctuation ; the two pairs of orange side-spots 

 large and broadly ovate and only narrowly separated from each other, and 

 occupying the sidemargins except at [the basal corners of the fourth segment 

 and on an extremely narrow actual margin ; the first pair of spots leave the 

 middle half of the disc black, but the second pair only rather more than the 

 middle third ; apical spot more separated from the second pair of spots than 

 they are from the first pair. Belly shining black with a small basal orange 

 sjjot, and the orange dorsal spots shining through on the margin. 



Legs blacker ; knees narrowly orange, and the hind trochanters obscurely 

 orange as well as the extreme tip of the tibiae and the soles of the tarsi. 



Wings with a brownish orange tinge. 



Length about 7 mm. 



This species is easily distinguished by its brilliaut black and yellow 

 markings, rather large size, and almost wholly black legs. My descrip- 

 tion has been made from a male taken by Mr A, E. J. Carter (and given to 

 me by him) and from a female without history (but apparently British) in 

 the Entomological Club collection ; it seems to be but little known, but has 

 a very close ally on the continent in 0. locuplcs Loew; this latter species 

 seems to be rather common in places as Becker records (Berl. Ent. Zeit., 

 xxxi., 97) the capture of fifty males and forty females at St Moritz, and 



