281 



The position of the last-named family has been somewhat in dis- 

 pute amongst taxonomists, but the larval and pupal characters un- 

 doubtedly ally it more closely with Chironomidae than with any other 

 family. 



SUPERFAMILY CHARACTERS 



Larva. — Head complete ; antennae elongate, except in some Cera- 

 topogonidae, retractile in Tanypinae; labial plate flat, usually 

 notched anteriorly. Thorax and abdomen with distinct segments, 12 

 in number ; pseudopods present upon prothorax and apical abdominal 

 segments, on prothorax only, or entirely absent; respiration carried 

 on by means of lateral prothoracic, abdominal, and anal spiracles, or 

 by apical spiracles and anal blood-gills, or by the latter alone. Some- 

 times the anal blood-gills are permanently exserted and located on the 

 latero-ventral margins of the apical segment, but usually they are en- 

 tirely or partly retractile, or they are situated at apex of last segment 

 and are somewhat leaf-like and not retractile. 



Pupa. — Head without chitinized protuberances; antennae curved 

 over eyes. Thoracic respiratory organs elevated, usually in the form 

 of a single tube, and not uncommonly filamented, rarely sessile. Legs 

 in Chironomidae recurved against base of venter of abdomen and apex 

 of thorax ; in the other families straight and not at all, or but slightly, 

 exceeding length of wings. Abdomen in Chironomidae and Orphne- 

 philidae with or without weak dorsal setulae, in Ceratopogonidae 

 with leaf-like or thorn-like bristles; apical segment in Chironomidae 

 usually with 2 or 4 pointed thorn-like protuberances. 



Imago. — Antennae consisting of 6 to 15 joints; palpi 2- to 5- 

 jointed, pendulous; proboscis in Chironomidae and Orphnephilidae 

 poorly developed, in Ceratopogonidae well developed and chitinized. 

 For synoptic characters see key to imagines on a previous page. 



Family CERATOPOGONIDAE 



After a careful examination of all the stages of this group and a 

 comparison of these with the various stages of other families of the 

 suborder I have decided to separate it, as a family, from Chironomi- 

 dae, in which it has been previously placed as a subfamily. 



FAMILY CHARACTERS 



Larva. — Head complete (PI. XLI, Fig. 15) ; mandibles (PI. XLI, 

 Figs. 13, 14) opposed, toothed or simple and hook-like; labium dis- 



