172 DIPTEKA. 



the six specimens in this author's collection, five have yellow halteres, which is the 

 usual colour, and one only has them black. Among the specimens before me a 

 single one from Cordova has a deep black knob to the halteres ; in the three others 

 the knob is yellow. I do not know how to explain this unusual anomaly. (Van der 

 Wulp has also noticed this discrepancy in Bellardi's description, cf. Tijdschr. voor 

 Ent. xxv. p. 90.) 



Arribalzaga (I. c. pp. 6 & 73) and van der Wulp (I. c.) have fully discussed the 

 further synonymy of this species. Certainty on those points can only be obtained 

 through the comparison of original specimens. However, I agree with Arribalzaga 

 that, judging from the description, Senobasis auricinctus, Schiner, cannot be the same 

 species. About the rest of the synonymy, as adduced by Arribalzaga (' Catalogo de los 

 Dipteros &c. p. 1 39), I cannot express any opinion. 



N.B. — I do not follow Arribalzaga and van der Wulp in calling Blepharepium the 

 genus to which this species belongs ; I think that it should be called Planetolestes, 

 Arribalzaga, as this author was the first to point out the principal characters which 

 distinguish it from the allied genus Diogmites, (Arribalzaga) Loew, namely, the absence 

 of bristles on the scutellum, and the different length of the pul villi on the front and 

 hind legs. The characters of Blepharepium, Rond., are applicable to several species of 

 Diogmites with an abdomen coarctate at the base (e. g. D. lindigii, Schin.), and I have 

 no doubt that Rondani himself would have taken the latter species for a Blepharepium. 

 Therefore JBlepharepium and Planetolestes are not one and the same genus, the former 

 being based on illusory characters. 



Planetolestes differs from Diogmites thus : — 



(1) It has no bristles on the scutellum, the latter being much less projecting ; in 

 Diogmites there is a pair of long bristles. (2) The pulvilli on the four posterior legs 

 hardly reach the middle of the ungues, and are therefore much shorter than those on 

 the front legs. (3) The macrochsetae on the sides of the mesonotum are smaller ; on 

 the post-alar callus one is not half as long as the other. (4) There are no macrochsetse 

 in front of the scutellum ; in Diogmites prsescutellar rows of bristles are of common 

 occurrence. 



Arribalzaga says there is no style at the tip of the antenna? ; I perceive a minute 

 style in my specimens — more distinct in the male, almost obsolete in the female. He 

 correctly describes : a pair of longitudinal rows of minute bristles on the mesothorax ; 

 but in my female specimens I perceive a third, intermediate, row which I do not see in 

 the male ; the lateral rows are double. The denticulate projection at the base of the 

 metatarsus noticed by Arribalzaga also exists in Diogmites, as well as in other Dasy- 

 pogonina provided with a hook on the front tibia?. 



