12 Transactions of the Society. 



throws light. The small size of these flies renders dissection very 

 difficult, and a study of a greater Dumber of species has shown 

 that several points in the 1904 paper are erroneous, or erroneous 

 in part. 



The cardines are not in their usual place, hut are aborted. I 

 was misled by my preparation, which quite agrees with the figure 

 on plate vii. (1904). What are marked as cardines are in reality 

 the edges of the submentum. This shows when the structures are 

 teased apart ; mounted in the ordinary way the appearance is 

 deceitful. The taste-hair at the end of each trachea is found in 

 many of the tropin of Diptera, but, so far as my observations go, is 

 never so large as it is in the Phoridee and Dolichopodidae. The 

 part marked h (hypopharynx) is not that, but a fusion of the 

 laciniee, only to be found in the Phoridse, and characteristic of their 

 mouth-parts. 



The trophi are peculiar in many respects, and present sin- 

 gularities not found in other families : — 



1. The armature differs in the sexes in the majority of cases, 

 though the genus Gymnophora appears to be an exception. This 

 difference is not a failure of mandibles as in Gulex or Tabanus, but 

 the labrum is armed and the bases of the tracheae bear strong 

 teeth in the female, while the labrum is quite simple and the teeth 

 less developed in the male (plate III. figs. 47, 48). 



2. In both sexes (though often smaller in the males) is found 

 the curious aculeation at the base of the cleft of the paraglossse. 

 This I homologise as the fused lacinia?, the cardines being quite 

 aborted or absorbed into the base of the lacinia?. In Gymnophora 

 arcuata Mg. and in the female of P. curvinervis Beck, the cardines 

 appear to be present, but. abnormally small and quite close to the 

 lacini;i' ; their broadened bases are quite recognisable. I know of 

 no similar migration of the parts in any insect, but a comparison 

 with what has come about in the Tipulida? and Bolichopodida? 

 makes me feel confident of this determination (plate III. figs. 38, and 

 plate IV. fig. 54) 



3. The cleft between the paraglossa? is very deep, and the 

 edges of the paraglossa? bordering the cleft, bear chitinous plates. 



4. The mandibles are fused into the mentum and send out 

 lateral processes as in many Stratiomyida? and Lonchopterida?. 

 (plate III. fig. 49, and plate IV. fig. 53). 



5. The presence of teeth on the paraglossa?, only found in the 

 specialised Muscidse, combined with the anterior position of the 

 maxilla?, and the ventral position of the mandibles, makes this 

 trophi peculiar (plate III. figs. 38, 45, and plate IV. fig. 54). 



G. The palpi are two-jointed in exceptional cases, as in Phora 

 concinna Mg. figured on plate ■ vii. (1904), also in P. trincrvis 

 Beck ? ; but in the majority of species they have annulated bases 

 very similar to the same part in Pipunculvs. They are labial and 



