Ecology of Marcus Island — Sakagami 
97 
Figs. 13-17. Some aspects of insect life on Marcus. Explanation in text. 
abundant in June; assemblage of Eobia in lamps, 
May to June, and August to October. 
These data are still insufficient but indicate 
the monotonous and inconspicuous phenological 
trends on this island. This may be also recog- 
nized from the occurrence of all developmental 
stages of Locusta, Landreva, and Utetheisa dur- 
ing our short stay. 
BIOGEOGRAPHICAL REMARKS 
Marcus is of little interest from the point of 
view of regional biogeography. According to 
Tuyama, who not only identified all plants col- 
lected by me but also kindly informed me of 
their distribution and ecological characteristics, 
all the plants are species of wide distribution 
and high vigor. After comparing the very sim- 
ple flora of Marcus Island with that of the 
Bonin Islands — where 46 per cent of a total of 
321 species are endemic, and where five endemic 
genera are found (Nakai, 1930) — it is prob- 
ably futile to discuss the phytogeographical 
position of Marcus. 
The same conclusion can be applied to land 
animals. According to Gressitt (1956), the is- 
land belongs by its location to the Oriental 
Zoogeographical Region, Polynesian Subregion, 
Division Polynesia Proper, and Subdivision Mi- 
cronesia. But the order of frequency of the vari- 
ous distributional patterns is: Tropicopolitans 
(including Indo-Pacificopolitans ) (18 spp.); 
Cosmopolitans (13); Pacificopolitans (6); Pan- 
Palaearctic (5); Endemic (4); Species with a 
