Cutiterebra and its Allies in the British Museum. 381 



G. atroXj Clark, belongs to a group of black or blue-black 

 species, which are clothed with black hair, either entirely or 

 with the exception of a tuft of yellow pile on the pleuras. 

 Much more material is necessary before the limits of these 

 species can be determined satisfactorily. 



Judging from the descriptions (Brauer's translation in the 

 case of that of C. atrox, Clk.), C. approximata, Walk., and 

 C. atrox^ Clk., are very closely allied. If the dimensions of 

 the latter as given by Brauer (' Monographic,' &c. p. 242) on 

 the basis of Clark's figure are to be depended upon, however, 

 C. approximata is a smaller and much more slender species. 

 The following are the dimensions of Walker's type (a 

 female) : — Length 21 millim. (correctly given by Walker as 

 "10 lines"); width of vertex 3 millim.; width of head 



8 millim. ; width of abdomen at base of third segment 



9 millim. ; length of wing 16 millim. 



The head shows only a single flattened, deeply punctured, 

 but ill-defined tubercle on each side, its base resting on 

 the eye opposite the antennas; there is no tubercle on the 

 cheeks beneath the eyes, as in the specimen from Trinidad, 

 which I have described as C. funehris ; the dorsum of 

 the thorax and scuteUum seems originally to have been 

 shining black ; the " dark cinereous tomentum " mentioned 

 by Walker is due to the dirty state of the typical specimen ; 

 pleune clothed with tufts of black pile, without a trace of 

 yellow ; dorsum and scutellum thinly clothed with shorter 

 black pile : abdomen metallic dark violet, shining, the fourth 

 and fifth segments more purple than the rest, the central 

 portion of the third segment somewhat greenish blue ; the 

 sides of the segments below sprinkled with the usual irregular 

 markings of greyish pollen, leaving rounded and irregular 

 patches of the shining ground-colour ; no trace of white 

 margins to the segments above. Legs : femora reddish at 

 the tips ; tibiae polliuose at the base ; tarsi apparently not 

 very broad ; front tarsi, at any rate, scarcely more than half 

 as broad as the corresponding pair in the typical specimen 

 of C. funehris, the first joint longer, the remainder more 

 compact and squarer. Wings somewhat narrow, uniformly 

 brown, not paler at the base in front. 



G. approximata, Walk., is distinguished from G. funehris^ 

 Austen, by its smaller size, more slender form, deeper violet 

 colour of the abdomen, narrower tarsi, and the absence of a 

 tubercle upon the cheeks. 



The typical specimen, which is the only one in the collec- 

 tion, is from British Columbia (J. K. Lord) ; it is labelled in 

 Walker's handwriting, and the description is attributed to 



