REVISION OF LEUCOSPIDAE 31 



The pronotal carinae seem a very striking character in some species but a closer 

 study reveals that their taxonomic value is very relative. They are generally 

 less developed in the American species which lack the discal carina. The 

 premarginal carina in them is often weak, replaced by a swollen bare ridge and this 

 may be present or missing e.g. in the speifera-group (sometimes even as intraspecific 

 variation). A similar case occurs in the African ^n'co/or-group: premarginal carina 

 missing in L. parvtUa. And within the groups with the discal carina developed, as 

 for example the elegans-group, this carina may be unusually high (e.g. L. ornata, 

 L. varicollis, L. carinifera), or reduced laterally (L. africana), or rather low 

 L. fallax, L. insularis). 



The mesoscutal cross-carina is developed only in the African fuelleborniana- 

 group, to separate it from the otherwise very close Oriental petiolata-group. 



Also the form of the dorscllum is useful in separating some species-groups, but 

 often only in combination with the other characters. In several species it is slightly 

 variable but in general, as a group character, it holds well. For example it is 

 convex, non-carinate in the o^mis-group, or apically bidentate in the australis- 

 group, both of which have a dorsal tooth on hind coxa. Only in the mentioned 

 cayennens is-group and in the gigas-group its form is rather varied. 



Whilst the presence or absence of a dorsal carina on fore femur and tibia are 

 used only as additional group characters of some American species, the shape of 

 hind legs, in particular of the coxal and femoral teeth and the apex of tibia, have 

 attracted attention of many authors. Girault (1915 onwards) used them to 

 separate Exoclaenoides, Parexoclaenus and Epexoclaenoides as different genera. 

 A relatively slender hind coxa with broad dorsal side (L. antiqua and the aruhni- 

 group) probably is a primitive, plesiomorph form. With the broadening of the 

 coxa the dorsal side becomes narrower (elegans-group) and turns first posteriorly 

 into a thin ridge (cayennensis-group, gigas-group, hopei-group, speifera-group) 

 often subserrate (hopei-group and dors igera-group) or forming a sharp meso-dorsal 

 carina (some species of the /nco/or-group; L. brasiliensis of hopei-group) , or 

 developing a thin broad lobe (hopei-group) which may be narrowed into a tooth 

 (egaia-group) . The outer side of the dorsal edge may suggest or form a tooth 

 (petiolata-group, fuellebomiana-group, L. regalis) which may be fairly conspicuous, 

 although beset with piliferous punctures (a^tms-group, australis-group, L. namibica, 

 L. holubi). As shown by the examples, also this character does not correlate 

 much with the other characters of the species-groups. 



The hind femur shows a similar situation (shown together with the coxa and tibia 

 in many text-figures). There seems to be every possible intergrade, in the most 

 crucial point within one species (L. africana, Text-fig. 126). One extreme is the 

 enormously swollen femur with very long second to fourth teeth, whilst the first 

 is much smaller (texana-gr oup, tricolor-group). At the next stage the femur is 

 less swollen but the teeth have still the same character (gigas-group, petiolata- 

 group). Then the teeth become gradually shorter and shorter (L. regalis, some 

 species of the elegans-group) , whilst the first tooth becomes broader and stronger 

 (mentioned Text-fig. 126), although still only about as long as the middle teeth. 

 The next form has the basal tooth distinctly the strongest (most American groups, 



