On the Rats usually included in Arvicanthis. 67 
8. Papilio horishanus, Mats. (PI. V. fig. 4.) 
We take this opportunity of figuring this very interesting 
Papilio. The specimen figured was taken at Gokansan, 
Formosa, in August 1914. 
This distinct species shows its relationship to kuehn?, 
Honr., from Celebes, in the delicate carmine patch on the 
hind wing below, this patch in kuwehni being small and 
restricted to the discal area. 
EXPLANATION OF THE PLATES. 
Prate IV, 
Fig. 1. Delias enniana kapaura, Roths., ¢. 
Fig. 2. dice eceicet, 3. 
Fig. 3, —— - 
Fig. 44 —— samarai, 3. 
Fig. 5. —— 52% 
Fig. 6. —— albertisi neyi, Ribbe, 2. 
PLaTE V. 
Fig. 1. Eribea eudamippus le moulti, 3. 
Fig. 2. Acca venilia jobina, 3. 
Fig. 3 
Fig. 4. Papilio horishanus, Mats. 
V1I.—On the Rats usually included in the Genus Arvicanthis. 
By Ouprietp THomas. 
(Published by permission of the Trustees of the British Museum.) 
THe variation in colour-pattern among the rats commonly 
included in the genus Arvicanthis is so great that one would 
expect that some generic or subgeneric division of them 
would prove ultimately advisable. Some species are with- 
out lines on the back, some have one, others four, and 
others again a larger number of stripes which may or may 
not be broken up into spots. 
Of names already existing within the group the earliest is 
Rattus, Donovan, but, as is shown in a succeeding paper, 
that is antedated by earlier writers for other animals. 
Then follow Arvicanthis, Lesson, and Jsomys, Sundevyall, 
both based on the Nile rat, A. niloticus, and finally Lemnis- 
comys, Trouessart, founded on the striped species, L. barbarus 
being taken as typical. Recently Mr. Heller * has recog- 
* Smiths, Misc, Coll, lix, no. 16, p, 12 (1912). 
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