TIPULID SUBFAMILY CERATOCHEILINiE. 359 



This species has been described from two preparations of Lt.-Col. Winn 

 Sampson, one of which ( cJ ) bears the date 25th May, 1900. Thej will be 

 deposited in the British Museum as types. 



Ceratocheilus longirostris, S , sp- u- (Ph 49. figs. 4, 10.) 



Only the male has been found ; this has ten joints in the antennae and the 

 second joint is slightly larger than in C. Winn-Sainpsoni ; the proboscis is 

 markedly longer than in that species ; the eyes appear to be even less 

 divided, but the head is rather pressed in the preparation and may mislead. 

 Structure of other parts as in Neoceratoclieilus Graliami. 



Wings with the second longitudinal vein longer and consequently the 

 subcostal cell larger than in C. Winn-Sampsoni ; in addition to the darkening 

 of the transverse veins, and the mark on the auxiliary and first vein, there 

 are three small stigniata on the costa at the junctions with the auxiliary, the 

 first, and the second longitudinal veins. The tip has not the markedly 

 lighter portion that is found in the other species, but is not Mdthout a 

 suggestion of its presence. 



Length of head and proboscis () mm., of which over 5 go to the proboscis; 

 length without proboscis 6^ nun. 



Habitat. S. Nigeria. 



Described from a preparation of Lt.-Col. Winn Sampson deposited in the 

 British Museum. 



Table. 



1 (2). Wings hyaline Neoceratocheilus Grahumi. 



2. Wino-s clouded 3. 



3 (4). Costa with one stigma Cevatocheilus Winn-Sumpsoni. 



4. Costa with three stigmata, proboscis much longer. ... C. longirostris. 



The remarkable specialization of the mouth-parts is a strikingly ancient 

 character, as the })alpi cannot be other than labial, and therefore the speciali- 

 zation dates from a period when the ancestors of the Tipulidse possessed a full 

 armature of the trophi. 



A comparison of the wing-venation in the two genera shows the second 

 longitudinal vein in process of obliteration and complete obliteration, a 

 common feature of the venation of many Nematocerous flies; while the 

 tendency of the veins to leave the lower portion of the wing is seen by the 

 position of the lower transverse vein in JVeoceratocJieihts, which genus is 

 obviously later in type than CeratocJieilus. 



Finally, the antenn?e show a stage which must have been gone through in 

 the progress from a filiform type to such a condition as exists in Brachycerous 

 flies such as Hllara or Empis. 



