2 Transactions of the Society. 



been examined, and a review of the tropin in the "peculiar family 

 of the Phoridte has shown so many fresh points, that additions are 

 desirable. 



I propose to keep to the arrangement of groups, and will as 

 formerly, for the sake of ease in reference, make any remarks on 

 family or genus in the section devoted to that group.* 



Group 1. — All parts distinguishable, except the labial palpi, 

 which are aborted. 



Simulidse. (Type S. reptaus L.) 

 Culicidte, the females only. 

 Tabanida^, „ „ „ 



Asilidie. 



Group 2. — The mandibles are fused into the labium, and the 

 labial palpi are aborted. 



(«) Raptorial, or bloodsucking. 



Empidie, with exceptions. 



Leptidse, „ „ (Type L. scoippacea L.) 



The genus Ceratopogon of the Chironomyidae. 



EXPLANATION OF PLATE I.—cout. 



Fig. 3. — Pharyngeal pump in Asihts crabroniformis L. The position is different 

 from that in Culrx, the anterior portion being to the left. 

 4.— Diagram showing a lateral view of fig. 3, and showing how the part is 

 worked in this species, 



,, 5. — Pharyngeal pump in an undetermined Asilus from Pegu. 



,, 6. — The same, on a small scale, showing the suhmentum and the hypo- 

 pharynx, to show their relative positions. 



., 7. — Portion of the base of the hypopharynx of Asilus from Pegu, to show a 

 supposed poison-gland. 



,, 8. — Pharyngeal pump in Empis livida L , to show the different mechanism. 

 On the right is shown the base of the hypopharynx and on the left the 

 pharynx. 



,, 9. — Pharyngeal pump in Tachydromia cursitans F., a minute predaceous 

 Empid. The position is again reversed, the pharynx being on the 

 right, and shows a bulbous swelling. 



,, 10. — Paraglossa of Hi/bos grossipes L. To show the "taste-cups." 



,, 11. — Labium of Leptis conspicua Mg. Seen from the ventral side; to show 

 the imbedded mandibles laterally disposed, and the tracheae of the 

 paraglossa? springing from plates. 



,, 12. — Labrum and hypopharynx of L. conspicua. Removed from the dorsal 

 side of the labium, and viewed laterally. 



,. 13. — Lacinia and maxillary palpus of L. conspicua. 



,, 14. — Mentum of ChrysopiVus auratus F., a genus of the Leptidse, nearly 

 related to L. conspicua. Thementum has been dissected out from the 

 ventral side of the labium, and shows the imbedded mandibles, which 

 here send out processes both at their posterior and anterior extremities. 



,, 15. — Mentum of Lonclwptcra flavicauda Mg., treated in the same manner as 

 fig. 14. 



,, 16. — Hypopharynx of L . flavicauda. Lateral view. 



,, 17. — Lacinia and maxillary palpus of L. flavicauda. 



„ 18. — Labrum of L. flavicauda. Dorsal view. 



