1893.] MR. E. E. ArSTEK ON NEW DIPTEEOUS INSECTS. lo7 



tbe type of the species : the specimen in question is about 8 mm. 

 in length, and resembles the female in general appearance ; the 

 face and cheels are, however, safEron-yellow, instead of pale yellon- ; 

 the frontal triangle has a bro\^Tiish median stripe extending from 

 the antenniferous projection nearly to the angle of the eyes : the 

 abdomen is narrower, and somewhat contracted and cylindrical at 

 the base ; the first segment is brownish in the centre ; the third 

 segment has a fairly broad posterior brown band, with the lateral 

 angles only faintly indicated ; the median brown mark projecting 

 from the anterior margin is oval in shape, and does not extend 

 further than one-fifth the length of the segment ; the tuim/s are 

 somewhat browner, and less yellow, but this is also the case in the 

 smaller of the two females mentioned above ; the posterior femora 

 have a narrow incomplete brownish band beyond the middle. 

 This specimen is likewise from the region of the Amazons (Bates). 



Baccha ceocea, sp. u. (Plate Y. fig. 6, S •) 



J . Length 8| to 9 mm. 



Closeh/ allied to B. crocata ; saffron-ijeJlow ; tJiora.v metallic, very 

 shitiinq, brown in the centre of the dorsum, U'ith two narrow abbre- 

 viated yellow stripes; abdomen narrow at the base, but exjjandiiui 

 re(/ularly to the end of the fourth segment, tvith brown bands and 

 indentations, but the third seymcnt with no brown at the basal angles ; 

 wings suffused ivith pale brown, aluke rudimentary; legs yellow, 

 posterior femora with a narrow but distimt brownish band beyond 

 the middle, darkest on the outer side. 



The chief differences between this species and crocata appear in 

 the front, thorax, and third segment of the abdomen ; the/*'0/ii is 

 shining yellow, instead of dull orange (the black dot above the 

 base of the antenna" is present) ; the thorax is very shining, and 

 the narrow yellow stripes which are situated on either side of the 

 median line are due to the ground-colour, and not to pollen ; 

 the metanotum is brownish, but there is no dark stripe extending 

 backwards to it from above tlie middle coxae ; the first abdominal 

 segment is brown in the centre, as is the case in the specimen 

 which I have considered as a male of crocata, but the absence of 

 brown from the basal angles of the third segment gives that 

 segment quite a different appearance ; there is likewise no brown 

 in the basal angles of the fourth segment, but this, so far as its 

 damaged condition permits me to judge, is likewise the case in the 

 specimen I consider to be a male of crocata ; in other respects the 

 brown markings of the abdomen are almost precisely similar to 

 those seen in crocata; the median brown stripe on the fourth 

 segment stops short of the anterior margin in the typical specimen, 

 but reaches it in the other example in the collection ; the wings 

 are less inf uscated than in the supposed male of crocata, and are 

 somewhat narrower and longer; the third longitudinal vein is 

 straighter, and the terminal portion of the fourth vein, closing 

 the first posterior cell, less sinuate. 



Brazil, region of the Amazons (Bates) : two specimens. 



