SIMULIIDAE OF AFRICA 23 



vestigial remnant of a fork. The almost completely undeveloped calcipala is also 

 similar to that of Prosimulium s. str. but the immature stages of Procnephia (in 

 which the pupa has lost the large pleural plates of the intermediate segments of the 

 abdomen and the larval hypostomium has the outermost tooth relatively small) are 

 not really separable from those of Paracnephia. The male hypopygium differs 

 slightly, but apparently consistently, between Procnephia and Paracnephia as the 

 ventral plate in the former is always rather flattened with a slender slightly curved 

 profile (Text-fig. 27), whereas in the latter the shape in profile, although diverse, is 

 always more expanded (Text-figs. 29, 30) : likewise the style in Procnephia is 

 excavate and markedly concave on the inner surface, whereas in Paracnephia there 

 is no such excavation (Text-figs. 32, 33). In the pupa the six or seven-filamented 

 gill, with the intertwining tips of the filaments, is distinctive in Procnephia, although 

 one species (brincki) of Paracnephia also has a gill of six filaments (though differently 

 disposed, since they diverge widely). 



Included taxa. Prosimulium (Procnephia) damarense de Meillon & Hardy ; 

 P. {P.) morotoense (McCrae & Prentice) ; P. [P.) rhodesianum Crosskey. 



Subgenus PARACNEPHIA Rubzov stat. n. 



Paracnephia Rubzov, 1962 : 1401. Type-species : Cnephia muspratti Freeman & de Meillon, 

 IQ 53> by original designation. 



Diagnosis. Costa with well formed spiniform macrotrichia intermixed with hair-like macro- 

 trichia. Vein Rs not forked. Calcipala present, small to well formed (Text-figs. 23-25). Claws 

 of 9 with well developed basal tooth. Gonapophyses of $ terminalia rounded-lobate (Text-fig. 

 34). Ventral plate of 6* widened apically in profile (Text-figs. 29, 30), in ventral view usually 

 appearing slightly 'lipped' (Text-fig. 28). Style of $ not concavely excavate on inner side (Text- 

 figs. 32, 33). Pupal gill with 10-22 filaments (except 6 in brincki). Pupal abdomen without 

 large pleural plates on segments 4 and 5, terga and sterna of these segments separated by a single 

 longitudinally striate area which at most is interrupted only by minute platelet-like spaces [but 

 see discussion]. Larval hypostomium with outermost tooth of each outer group of teeth shorter 

 than the main tooth of the outer group (Text-figs. 51-53). Larval mandible with saw- 

 like series, usually about 12 in number, of mandibular serrations, these most often on rather 

 expanded flange. 



Bionomy. So far as known, as for Procnephia (see above). 



Distribution. South-West Africa and South Africa (Map 1), but very similar 

 forms, possibly consubgeneric, present in Australia and Central America. 



Discussion. The subgenus Paracnephia, as here re-defined in subgeneric status 

 within the genus Prosimulium s.L, contains all the forms (except damarense) that 

 were placed in Cnephia by Freeman & de Meillon (1953) and in the genus Para- 

 cnephia by Rubzov (1962), together with the species described in Cnephia by de 

 Meillon (1955). Although the included species are slightly diverse, and two (turneri 

 and herero) are still known only from the female holotypes, they are sufficiently 

 uniform in their main characters to allow of a reasonably firm definition of the 



