14(3 Mlt. E. E. AUSTE>- 0>' iSEW DIPTEROUS IXSECTS. [Jail. 17, 



first segment steely, with a taft of black hairs projecting from the 

 anterior angles, behind ^hich is a taft of yellow hairs ; second 

 segment steely on the anterior third above, on the sides for more 

 than halfA\ay, and on the hind margin, the remainder of the 

 segment dull black, with a yellow dot on each side ; third segment 

 steely on the lateral margins, and with a narrow transverse steely 

 band in front and behind, elsewhere dull black, ^ith four oval 

 yelloM' dots arranged in the form of a quadrilateral, the anterior 

 pair twice as far apart as the posterior : fourth and fifth segments 

 steely on the lateral and jwsterior margins, else^^ here dull black, 

 and each \\ith four oval yellow dots arranged as on the third seg- 

 ment ; genitalia small, concealed : the abdomen is broadly spatu- 

 late, expanding from the base of the third segment to the posterior 

 margin of the fourth, and contracting thence to the ti]) : the 

 second segment is stout and cylindrical, with a fringe of hairs on 

 each side, yellow in front and black behind ; the remainder of the 

 abdomen is sparsely clothed with short appressed black pile. Leys 

 black, with short, close-fitting black pile; the tarsi ilattened. 

 WiiKjs suffused with brown, with a darker area at the base, which 

 is paler towards the posterior margin, and extends a little beyond 

 the anterior cross-vein on the costal side : alvlo' well-developed. 



Ega, Brazil {Bates) : one specimen. 



This species is allied to Bacclta adspersa, Fab., but is at once 

 distinguished by the infuscation of the entire wing. The terminal 

 section of the fourth vein is also much more oblique in this s])ecies 

 than in B. adspersa. 



Baccua LEvissiMA, sp. n. (Plate I\'. fig. 15, S •) 



($ . Length 10| to 11| mm. ; length of wing 6| to 7 mm. 



MdaUiv hroazi'-hJacl\ ivWi dead-hlach vwrJdngs on the ahdomen ; 

 the latter (jreathj attenuated : iviuf/s very short, infuscuted ; ahdce 

 ritdimcniari/. 



Face and clieels metallic steely black, clothed (except on the 

 tubercle) with cinereous ])ollen; facial tubercle prominent. Front 

 \\itli a pentagonal dead-black patch in the angle of the eyes, on 

 each side of which, ^hen viewed from behind, is a shimmering 

 \\hite dot : front elsewhere and antenniferous process metallic 

 black, the latter with a flattened rugose area above. Vertical 

 triangle black ; the short pile on the front and vertical triangle 

 black. Antennce small ; the first two joints black, the third 

 l)row)i, oval ; arista blackish brown. Occiput black, A^ith silvery 

 pollen, and fringed with short whitish hairs. Thorax rather dull, 

 metallic broiue-black on the dorsum, shining metallic greenish 

 black on the pleurte ; a narrow dead-black median stripe on the 

 anterior part of the dorsum, not extending beyond the region of 

 the transverse suture : on either side of this stripe the dorsum in 

 front is brownish pollinose, when viewed from behind or from 

 the side. Scutellum metallic black; scutellum and dorsum finely 

 jnmctate, almost bare. Abdomen : first segment metallic steely ; 

 second segment steely, \Aith a broad dead-black transverse baud, 



