210 



tory organs longer than width of thorax ; or if the armature of ab- 

 domen is very weak the thoracic respiratory organs are not tube- 

 like but acute apically Limnophiljnae* (p. 220). 



IMAGINES 



1. Only one submarginal wing-cell present 2 



— Two submarginal wing-cells present 4 



2. Antennae with 14 segments Limnobiinae. 



— Antennae with 16 segments 3 



3. Tibial spurs present Cylindrotominae. 



— Tibial spurs absent Rhamphidiinae 



4. Tibial spurs absent Eriopterinae. 



— Tibial spurs present 5 



5. Subcostal cross-vein proximad of base of second vein . . . Pediciinae. 



— Subcostal cross-vein distad of base of second vein 6 



6. Antennae with 16 or more segments 7 



— Antennae with at most 10 segments Hexatominae. 



7. Seventh vein short, abruptly deflected towards anal angle 



Trichocerinae. 



— Seventh vein normal, not deflected towards anal angle 



LlMNOPHILINAE 



Subfamily CYLINDROTOMINAE 



This subfamily includes but four genera, each containing from 

 one to four or five species, and because of the peculiar anatomical 

 characters of the different stages it may yet be considered as entitled 

 to separate family rank. I have treated the subfamily in this paper 

 as belonging to Limnobiidae. 



SUBFAMILY CHARACTERS 



Larva. — Head similar to that of Tipulidae, the dorsal surface 

 arcuate, heavily chitinized, and with 2 slits which usually extend proxi- 

 mad of the middle. Antennae slender, longer than maxillary palpi. 

 Mandibles stout, with a strong apical tooth, and several smaller teeth 

 along the lower margin. Labial plate similar to that of Tipulidae, 

 the central tooth simple or bifid. Thoracic and abdominal segments 

 with long fleshy spine-like processes which may be either simple or 

 more or less furcate. Apical segment with 4 slender processes; 

 spiracles rather small. 



Pupa. — Head without projections ; antennae curved over eyes. 

 Thorax very short; respiratory organs long and slender; wings ex- 



*I do not know what characters may serve to separate pupae of Limnophilinae 

 and Trichocerinae. 



