NARRATIVE OF THE CRUISE. 
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one of those eases of protective mimicry so often described in works on natural 
history; it mimics very exactly Ophthalmis lincea (fig. 192), another moth belonging 
to a different family. 
Mr. Butler writes : — “ This is one of those instances of mimetic assimilation so perfect 
as to catch the eye at the first glance. That the Agaristid is the species copied cannot 
Fia. 191 . — Artaxa simulans, A. G. Butler. Fig. 192 . — Ophthalmis lincea, Cramer. 
be questioned, since it is not only a common form, but it belongs to a group which, like 
the allied Zygsenidse, is evidently distasteful to insect enemies.” 1 
Another illustration of this protective mimicry occurs in a new species of Butterfly 
obtained at the Arrou Islands (see p. 548), in which the Butterfly ( Papilio alcidinus, 
Fig. 198 , — Alcidis aruus, Felder. 
fig. 194) imitates a day-flying Moth {Alcidis aruus, fig. 193) common in the 
same locality. Mr. A. G. Butler, who described the species, calls attention to an 
important peculiarity, in addition to the general resemblance of the upper sur- 
face : — “ On the under surface, however, is a character which strongly supports the 
1 Ann. and Mag. Nat. Hist., ser. 5, vol. xiii. p. 200, 1884. 
