Dre 
the species being sexually dimorphic, or di- and polymorphic in 
both sexes, e. e. Papilio ariarathes ESP. (1788), P. harmodius 
DOUBL. (1846), P. thymbreus BOISD. (1836), etc. 
Among the American Mymphalinw, there are some genera 
related to our Vanessas, whose species have a very close similarity 
to other Lepidoptera in many and most diverse directions. Among 
the species of Phyciodes, Gnathotriche and allies we find many 
which bear a confusingly near likeness in coloration to Pierids, 
or Neotropids, or Acræids. There are several instances of poly- 
morphism and sexual dimorphism among them. The facies of some 
of the Phyciodes is so much Acrwa-like that a few species have 
actually been described as Actinote (or Acrwa) by a very able 
entomologist. The resemblance of the dimorphic species is hetero- 
trope, one form resembling one species of Actinote and the other 
form another Actinote. Also in Phyciodes and Gnathotriche 
intermediate individuals are rare, as in the Papilios we have dealt — 
with, while there are, of course, no intermediates between the 
distinct species of Actínote which act as « models ». 
Parallel cases to those of Phyciodes and allies are comparatively 
rare among the Oriental Vymphaline, but Africa possesses in 
Pseudacrwa a genus which exhibits heterotrope resemblance in 
an exceptionally high degree. Unlike Phyciodes, however, its 
similarity is directed only towards Acrwinw, especially the genus 
Planema. As Pseudacrea contains monomorphic and polymorphic 
species, and as these species are either non-mimetic, or resemble 
one model, or bear the facies of several specifically distinct models, 
the genus is as fascinating for the systematist as it is interesting 
for the exponent of Mimicry and his adversary. We have figured 
(pl. XXI, fig. 1a-4a) two Pseudacrew, which are each similar to 
one species of Planema. We will now deal with one dimorphic 
and one polymorphic species and the various distinct Acrwine 
which they resemble. 
Pseudacrea clarki BUTL. (1892) occurs in two forms, one 
bearing the pattern of Acrwa orina HEW. (1874) and the other, 
described as P. landbecki DRUCE (19009), being an almost exact 
counterpart of Acrwa egina CRAM. (1775). The two forms of 
Pseudacrea are connected by intergradations, while the two 
Acree belong to different sections of the genus. Nobody who has 
examined a series of specimens can seriously doubt that P. clarki 
and /andbecki are individual forms of one Insect. However, 
