1889.] 425 



specimens) I find several which have the bases of these parts more or less blackened ; 

 so I have arrived at the conclusion that M. separata, Meig., and M. grandceva, Zett., 

 are the same.* 



SPILOGASTEK, Macq. 



S. QTJADRIMACIXLATA, Fall. 

 In my list I followed the example of Rondani, and named this species quatuor- 

 maculata ; it is more correctly designated quadrimaculata by Fallen. 



S. ATRIPES, sp. n. 



As I stated in the first part of my list, the £. duplicata, Meig., must be looked 

 upon as the representative of a group of several closely allied species, or perhaps 

 only varieties ; which are very difficult to define or discriminate from each other. 

 In June last I captured at Hornsea, near Hull, two males of a species which though 

 nearly allied to the one which I have described as the true S. duplicata of Meigen,f 

 is decidedly different, and is also distinct from S. duplaris, Zett., as well as from 

 S. communis, Desv. From its black legs I shall call it S. atripes. 



<J . Nigro-cinerea, oculis subcontiguous; arista longe-plumata, thorace- antice 

 albo-cinereo quadristriato setis dorso-centralibus tribus pone-suturam ; abdomine 

 quadrimaculato, segmentis subanalibus prominentibus ; pedibus prorsus nigris. 



Long., 7 ad 8 mm. 



Head : eyes subcontiguous ; arista long haired. Thorax clear ashy-grey, with 

 front margin almost white ; marked with four very distinct shining black stripes, 

 the middle pair straight, extending from the front edge to a little behind the trans- 

 verse suture, the lateral ones maculiform, shortened in front and extending back- 

 wards nearly to the scutellum ; dorso-central bristles five in number, two before and 

 three behind the suture. Scutellum clear grey and immaculate. 



Abdomen cylindrico-conical, with four small black spots, two on the second and 

 two on the third segment ; subanal segments large, and furnished with a prominent 

 process, which projects forwards and ends in a hairy tuft near the middle of the 

 venter. Legs quite black, armed as in S. duplicata. 



Wings clear, transverse veins unclouded, external one oblique and slightly 

 sinuous, costal spine large. Alulets white. Halteres yellow. 



This species differs from all the others in the group by having only three dorso- 

 central thoracic bristles behind the transverse suture ; S. duplicata, S. duplaris, and 

 <S. communis having four ; the form and size of the subanal male processes are also 

 different, they being larger and more prominent in S. atripes than in either of the 

 other three species, which all have them very similarly developed ; lastly, this species 

 has the legs quite black, whereas, in each of the others, the knees, and often the 

 hind tibiae, are somewhat rufous, even in the males. 



I could not find a female. 



S. FRATERCTT1A, Zett. 



This species is nearly allied to S. pertusa, Meig., in size, colour, &c, but differs 



by having the arista less pubescent (it is nearly bare towards the apex), and the legs 



darker in colour. In S. pertusa the fore femora and tarsi only are black, and the 



hinder femora and all the tibiae are fiavescent ; while in S. fratercula, besides the 



* M. separata of Schiner is a distinct species, which has the arista plumose. 



t The Mydina nigripes of R. Desvoidy is considered to be synonymous with S. duplicata, Meig. 



