30 



Fresh-water Biology 



{Continued from page 28) 



6 — Lobes of disc fringed with long hairs Holorusia 



— Lobes of disc fringed with short hairs or none Tipula 



7 — Body covered with flat leaf-hke projections Triogma 



— Body bare 8 



8 — Body depressed ; no lobes on spiracular disc Elliptera 



— Body cylindric; lobes present on spiracular disc 9 



9 — Spiracular disc with 5 lobes 10 



—Spiracular disc with less than 5 lobes 12 



10 — Creeping welts beneath abdominal segments Ramphidia 



— No creeping welts present 11 



11 — Color green Erioptera 



— Color not green Trimicra 



12 — ^Spiracular disc with 4 lobes 13 



— Spiracular disc with 2 lobes 16 



13 — Spiracular disc defined by ridge above; hair fringes short Hexatoma 



—Spiracular disc not defined above by ridge; hair fringes long 14 



14 — Disc bare across upper border Eriocera 



— Disc hairy across upper border 15 



15 — Lower border of spiracular disc cross lined with black Pilaria 



— Lower border of disc little or not at all crossed with black Limnophila 



16 — Creeping welts black; spiracles invisible Antocha 



— Creeping welts if present not black; spiracles easily visible 17 



17 — Lobes long and densely clothed with long hairs Pilaria 



— Lobes bare, or nearly so 18 



18 — Lobes slender, tapering, body segments with transverse rows of bristles . Rhaphidolabis 

 — Lobes shorter, more blunt; body segments smooth 19 



19 — Anal gills very unequally 2 segmented Pedicia 



— Anal gills more equally divided into a larger number of segments 20 



20 — Spiracles separated by their own width Tricyphona 



— Spiracles separated by twice their own diameter Dicranota 



KEY TO THE GENERA OF AQUATIC NEUROPTERA: LARVAE 



1 — Large forms with biting mouth parts. Sialididae 2 



— Small forms with piercing mouth parts. Hemerobiidae 4 



{Continued on page 32) 



Genera Figs. 



Atherix 23 



Anopheles 1 



Bibiocephala ... 20 



Blepharocera. . . . (20)a 



Ceratopogon. ... 17 



Chironomus 10,18 



Chrysops (21)6 



Corethra 19 



Culex 2,3 



Dixa 13,14 



Euparyphus. . . . 26(25) 



PLATE 12. MISCELLANEOUS DIPTEROUS LARVAE 



Length Distr. Waters Genera Figs. Length Distr. Waters 



16 G lotic Odontomyia. . . . 25 12-50 G static 



10 G static Psychoda 15,16 6 G static 



10 W lotic Sarcophaga 22 14 E static 



8 E, W lotic Sepedon 5-8 11 G static 



5 G static Simulium 11,4 7 G lotic 



2-22 G both Stratiomyia 24 27-40 G static 



12 G static Tabanus 21 20-55 G static 



8 G static Tanypus (12)c 6 G both 



7-12 G static Tanytarsus 12 3-7 N both 



6-10 G static Tetanocera 9(5.6) 11 G static 



12 G lotic 



a Differs by lack of lateral pedunculate processes. 



b Differs by having the last antennal joint longer than one preceding. 



c Differs by lacking the peduncle under the antenna. 



