552 Appendix to Rc^K. St. Aubyn Rogers' Bionomic 



persistency, exactness, and completeness with which they 

 reproduce the pattern and colouring of their models, the 

 very variable and abundant Flana/t/t — the species of 

 "which, though few in number in comparison with the 

 &\Yied Aow/v, are very difficult to distinguish satisfactorily. 

 Every variation in both sexes appears to be faithfully 

 copied throughout tropical and sub-tropical Africa wherever 

 the genus Plancma prevails, Aurivillius (Rhop. TEthiop., 

 pp. 5*30-1) has recorded eight instances in which this 

 mimicry is palfiable, and the case here noted is an addition 

 to that list. The mimicry mentioned by Mr. S. A. Neave 

 (Novit. Zool., xi, p. 333, 1904) of the British East African 

 form of Plancma tellv.s, Auriv., by Fscudacrxa terra, Neave, 

 — captured on the same day at Entebbe — is another 

 recorded instance ; and, looking to the rather dull and 

 unattractive aspect of these buttertlies, and to the evident 

 comparative raiity of the Fsevdacrnw,, it may reasonably 

 be conjectured that they have not been very assiduously 

 observed or collected, and that the extension of field 

 research will bring to light more mimicries between 

 members of these two genera. 



It is a pleasure to name the species here described 

 after the author of the very interesting memoir to which 

 this is an appendix, not only in recognition of his valuable 

 services to African entomology, but in view of his having 

 himself (see above, pp. 508 and 523) pointed out the 

 mimetic relation existinsr between this Pseudacrt'ea and 

 Flancma montana. Mr. St. Aubyn Rogers has recorded 

 that the ^ of the Psciulacr/i'a was sent to liim from Shimba 

 ("IG miles W. of; about 1,200 ft."), while the $ was 

 captured by himself at " Rabai, 14 m. N.W. of Mombasa, 

 on July 28, 1906." 



Psciidacriea trimcnii, Butler.* 



The intimate alliance of this form of Pscndacr/va with the 

 West African P. hoisduvalii, Doubl., was recognised by me 

 in 1869 (Trans. Linn. Soc. Lond., xxvi, p. 517), and after- 

 wards better explained with the aid of fuller material in 

 1887 and 1889 (S. Afr. Butt., I, p. 298, and III, p. 405). 

 I showed how closely in both sexes trimenii, the South- 

 Eastern form, copied Aco^iea acara, Hevvits., of the same 

 region, just as hoisduvidii mimicked the West African 



* Ent. M. Mag., xi, p. 57 (1874). 



