1832.] 203 



Zett. The females of H. incisurata and H. scalaris are very similar, but may be dis- 

 tinguished by the neuration of the wings, the third and fourth longitudinal con- 

 verging a little in the latter, and being almost parallel in the former species. It is 

 not very common, but generally distributed. 



H. mantcata, Meig. 



The males of this pretty species are characterized by having the anterior knees 

 pale, and also the fore tibia?, with the exception of their apices, which are black, 

 thickened, and furnished on their outer sides with a little tuft of black hairs, which 

 is sometimes adpressed so as to be easily overlooked ; a long straight spine also pro- 

 jects downwards from the base of each middle coxa. The females may be distin- 

 guished by the pale colour of the fore tibia?. Not common. 



H. aemata, Meig. 



This little species differs from most of the others by having the abdomen wide 

 and less elongated. Meigen's description is very correct, but he omits to mention 

 that the posterior tibia? are curved as well as thickened, and ciliated with longish 

 hairs on both sides. The females of this and many other species of Homaloyrnia 

 are very difficult to determine, unless they are captured together with the males. 

 Generally distributed. 



H. spissata, sp. n. 



Mas, niger nitidus, abdomine oblongo depresso glauco, linea dorsali angulata 

 .ornato ; femora intermedia subtus hispida ; tibia intermedia nuda abrupte spissata ; 

 tibia postica intus ciliata. Long. 2? lin. 



Head : eyes sub-contiguous ; arista bare. 



Thorax, with the scutellum, black, shining, and unstriped. 



Abdomen oblong and depressed, grey with glistening white reflections when 

 viewed from behind, and appearing of a brownish-black colour when seen from before. 

 It is marked by an interrupted dorsal band, which is dilated at the base of each seg- 

 ment into a triangular spot ; anal processes very small. 



Wings slightly nigrescent, third and fourth longitudinal veins parallel ; external 

 transverse vein nearly straight and upright, separated from the internal transverse 

 vein by about twice the distance that it is from the termination of the fifth longi- 

 tudinal. 



Scales of Calyptra of moderate size and unequal length, and of a sordid white 

 or brownish colour. Halteres yellow. Legs black, with the exception of the bases 

 of the anterior tibia?, which are testaceous ; front pair simple ; middle femora fur- 

 nished beneath with longish black bristles, not extending to the apex, and arranged 

 in two parallel rows ; coxa? without spines ; middle tibia? abruptly thickened or 

 tuberculated on their inner sides at about one-third from the lower end ; tubercle 

 smooth, not ciliated ; posterior tibia? slightly curved, somewhat thickened, furnished 

 with a few long hairs in the middle of their inner surfaces, and with a number of 

 bristles and hairs of irregular lengths on their outer sides. 



This is possibly the H. armata of Macquart ; it differs from H. armata of 

 Meigen, and also from H. manicata of Meigen, by having the tubercular projection on 

 the middle tibia? smooth and not bearded with 6hort hairs as in both those species. 



