60 R. W. CROSSKEY 



3 <$ hypopygium with median sclerite deeply cleft Y-shaped ; style heavy and pro- 

 duced distally beyond level of insertion of the spinule ; paramere broad and 

 irregular plate-like ; ventral plate without definite median keel, but with haired 

 apical lip. Cocoon (in extra-limital forms) often with elongate median down-curved 

 process ......... latipes- group (p. 60) 



- o" hypopygium with median sclerite parallel-sided and rod-like, or if dilated apically 

 not deeply cleft (except in loveridgei) ; style, even if broadly truncate, not notice- 

 ably produced distally beyond level of insertion of the spinule ; paramere narrow 

 and elongate ; ventral plate with a haired median keel (Text-fig. 101). Cocoon 

 with or without short triangular median projection but without long horn-like pro- 

 cess .......... ruficorne- group (p. 61) 



latipes-group. Postnotum bare (except in occasional specimens). Styles large and broad 

 apically, produced beyond level of spinule insertion ; ventral plate large and broad, without 

 median keel, basal arms directed forwards ; parameres in form of irregularly shaped plates each 

 bearing one long strong parameral hook ; median sclerite characteristic, Y-shaped. Pupal gill 

 with 4 filaments (except in North American species croxtoni Nicholson & Mickel and wyomingense 

 Stone & DeFoliart with 8 filaments and gouldingi Stone with 6 filaments). Cocoon without 

 neck, simple or with long single or paired median horn-like process. Larval antenna without 

 secondary annulations, with or without one or two small supernumerary mandibular serrations. 

 Larval postgenal cleft normally shorter than or subequal in length to postgenal bridge, rounded 

 anteriorly or subquadrate, sometimes forming only a slight notch in posteroventral margin of 

 head. 



This is the predominant species-group in both the Palaearctic and Nearctic 

 Regions ; it is absent from the Ethiopian and Malagasy Regions, but occurs in 

 North Africa (Morocco). The group appears to be absent from most of the Oriental 

 Region, yet is undoubtedly present in Java, where two species occur, S.(E.) 

 tosariense Edwards and S.(E.) tjibodense Edwards, that were originally described by 

 Edwards (1934) as varieties of latipes Meigen : that these taxa belong in the latipes- 

 group and are very similar to European latipes has been confirmed while preparing 

 the present paper from material of the type-series in the British Museum collection. 

 In an earlier paper (Crosskey, 1967a : 33) it was suggested that no species of the 

 latipes-groxxp occur in the Old World tropics, but this overlooked the presence of the 

 two Javanese forms mentioned above. The group is apparently not represented in 

 the Canary Islands, although both the aureum-group and mficorne-gvoup occur there. 



The latipes-gvonp is best differentiated from all other groups by the very distinctive 

 male hypopygium with very deeply divided median sclerite and heavy styles of a 

 constant and unique shape : the styles are broadly truncate apically but protrude 

 beyond the level at which the inwardly and forwardly directed spinule is inserted, 

 and are twisted so that the apical part is bent inwards (well shown in figs. 71-74 in 

 Davies et al., 1962). The group is most closely related to the ruficorne-gxonp, as 

 discussed further below. 



S.(E.) latipes (Meigen) itself is the type-species of Enderlein's genus Cnetha, of 

 which Pseudonevermannia Baranov is a junior objective synonym, and if at any time 

 the subgenus Eusimulium is further subdivided into named subgenera then Cnetha 

 Enderlein, 1921, will be the oldest genus-group name available (other than Never- 

 mannia Enderlein dating from the same publication) for the residual concept after 

 separation of Eusimulium proper (i.e. the aureum-group, discussed below). 



