220 



ME. W. WESCHE ON THE LABIAL ANT) 



labial palps." Meinert *, of Copenhagen, has done much work on the trophi throuo-hout 

 the order. He has drawn, in a most admirable manner, the mouth-parts of the various 

 families, but has passed over the large group of the Anthomyiidge, considering it typified 

 by the Muscidse. According to Dr. Sharp f, Meinert (who writes in Danish) considers 

 that not only the appendages to a head-segment, but also part of the body of the 

 segment, may be used in the construction of the mouth-organs. 



H. J. Hansen J, also of Copenhagen, has published beautiful drawings of the mouth- 

 parts. His work is in Danish, with a Latin explanation of the plates. His studies were 

 mostly confined to the Ortborrhapha, Tabanus being elaborately treated. A novel and 

 unsatisfactory terminology is to be found both in tbis and in Meinert's work. 



Fig. 1. 



Trophi of Blatta. 

 The lettering as in Plates 8 and 9, as explained on page 229. 



In the order Hemiptera the rostrum is considered homologous with the proboscis in 

 Diptera. Those morphologists who have derived the labella in Diptera from the labial 

 palpi have included the rostrum in their theory. In 1901, Dr. N. Leon §, a professor 

 at the University of Jassy, in E-oumania, found rudimentary labial palpi on the rostra of 

 several aquatic Hemiptera. 



I shall now endeavour to homologize the proboscis of Musca with the typical ti'ophi of 

 Blatta, as that has an intimate connection with the labial and maxillary palpi. The 



* ' Trophi Dipterorum ' (Kjobenhavn, 1S81, 4to). t ' Cambridge Natural History,' Insects, part n. p. 444. 



j ' Fabrica oris Dipterorum,' 1883. § ' Eecherches morphologiques sur les pieces labiales des Hydrocores.' 



