26 R. W. CROSSKEY 



Simulium have more than one) ; the X-shaped sclerite of larval abdomen has a 

 backwardly-directed strut from each anterior arm in Austrosimulium which is absent 

 in other genera of Simuliini, and many forms show a ring-like accessory sclerotiza- 

 tion around the last larval abdominal segment which is also normally absent in the 

 other genera (though traces of such annular sclerotization are found in some 

 Simulium larvae from Madagascar and New Guinea). Austrosimulium pupae lack 

 dorsal spine-combs on the terminal abdominal segments like the pupa of Afro- 

 simulium and some Simulium but usually have some multiramous hooklets similar 

 to those of Metacnephia. The adult of Austrosimulium resembles Simulium very 

 closely in having both well developed calcipala and pedisulcus (both of these features 

 are virtually absent in Metacnephia and only the pedisulcus is well developed in 

 Afrosimulium) ; the wing has hair-like setae only on the apical part of R\ whereas 

 in Simulium vein Ri almost always has some spiniform setae in addition (but not 

 in subgenus Hebridosimulium Grenier & Rageau from the New Hebrides in which 

 R\ has hairs only). The rectal gills of the Austrosimulium larva are always simple, 

 whereas they are very often compound, with numerous finger-like secondary lobules 

 in Simulium larvae. Taking all characters together, Austrosimulium may be 

 accepted as a valid genus, although certainly very close to Simulium Latreille s.l. 



METACNEPHIA gen. n. 



Type-species : Cnephia saileri Stone, 1962. 



Genus of uncertain position, tentatively assigned to Simuliini and showing follow- 

 ing combination of characters : 



Diagnosis: o"?- Antenna with 11 segments. Head and eyes normal. Pleural membrane 

 usually haired [as in type-species], sometimes bare. Mesepisternal sulcus deep but sometimes 

 widened, almost complete anteriorly. Katepisternum bare. Costa with spiniform and hair-like 

 macrotrichia. Vein Rs simple, Cu^ sinuous. Basal cell present. Basal section of radius 

 haired. Wing membrane with normal microtrichia. Fore tarsus slender. Calcipala absent or 

 minute. Pedisulcus absent. 5* : hypopygium with simple tapering or slightly truncate styles, 

 style with one apical spinule; ventral plate lamellate, haired, transverse or subtriangular; para- 

 meral hooks numerous; median sclerite elongate and cleft apically. $ : cibarium unarmed. 

 Claws with large basal tooth. Gonapophyses simple, bluntly rounded or truncate lobes. Pupa : 

 Gill arborescent, 13-150 filaments with branching usually in basal half of gill, when fine filaments 

 very numerous these sometimes arising from a few large bulbous trunks. Abdominal cuticle 

 largely pale, delicate and membranous, cast pelt of pupa therefore without conspicuous brownish 

 sclerites ; no differentiated pleural plates, or conspicuous longitudinally striate areas. Last 

 segment with pair of small blunt terminal tubercles. Eighth and ninth (sometimes only the last, 

 ninth) abdominal segments laterally with grapnel-like or anchor-like divided hooklets (Text- 

 fig. 35). Abdominal segments 7 and 8 (sometimes also 6 or 5 and 6) with backwardly-directed 

 spine-combs. Normal basic abdominal onchotaxy (i.e. four hooks each side dorsally on seg- 

 ments 3 and 4, two close-set hooks each side ventrally on segment 5 and two widely spaced hooks 

 ventrally each side on segments 6 and 7) supplemented by additional spinous, often recurved, 

 setae on some or most segments, including transverse row dorsally on segment 2 (sometimes also 

 segment 1), extra setae outside main hooks dorsally on 3 and 4, some setae ventrally on seg- 

 ments 3 and 4 (sometimes also 2), and sometimes extra ventral setae on segment 5, occasionally 

 other slight variants. Cocoon shoe-shaped, form discrete and neck often well raised from sub- 



