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Psyche 
[September 
(Darlington, 1957), using the equatorial Atlantic currents. I think 
Halocoryza is unlikely to travel long distances by air, but part of the 
trip could have been made in this way. If so, a raft should pre- 
sumably have the same catching effect as an island. Regardless of 
the mode of travel, however, the carabid faunas of mid-Atlantic 
islands are of predominantly Old World origin (e.g., Lindroth, 
i960; Wollaston, 1865). 
The relationships of Halocoryza further indicate an African origin. 
Its closest relative is the American Schizogenius (which is probably 
derivative or at least shared a direct common ancestor with Halo- 
coryza), but no other related genera occur in the Americas. In 
Africa, the nearest relative is Lophocoryza, a relict and certainly 
non-derivative genus. The Indo-African genus Coryza is distantly 
related and seems to link Halocoryza and Lophocoryza with other 
Old World clivinine genera. 
The origin of Schizogenius from an early invasion of the Americas 
by some Lophocoryza-LIalocoryza stock, followed by a secondary 
invasion of Halocoryza , can readily be explained by the “taxon-cycle’ ’ 
mechanisms outlined by Wilson (1961). However, it seems unlikely 
that multiple trans-Atlantic migrations have taken place, even though 
Halocoryza is a relatively good candidate for such crossings. No 
irreversible characters of the genus conclusively demonstrate an in- 
direct relationship with Schizogenius. Moreover, some characters of 
Halocoryza are found, I think primitively, in some Schizogenius 
(abbreviated paramedian clypeal carinae; paralateral pronotal sulci; 
paramedian ambulatory setae on sternum six in both sexes; short hind 
tarsi; moniliform antennae; and elytral intervals three, five, and seven 
with setigerous punctures). 
Therefore, an alternative proposal merits mention. If but a single 
invasion occurred, it would follow that modern Halocoryza was 
directly ancestral to Schizogenius. The model for such direct ancestry 
is simple. Halocoryza at the time of invasion could have been no 
more different from extant Old and New World species than the 
latter now are from each other, and must have had the same adapta- 
tions for a seaside habitat then as now. One would not expect a 
rapid rate of evolution in a group of widespread species well adapted 
to a stable environment. That is, Halocoryza may be considered as 
an escapee from a changing environment (Maslin, 1952). But 
populations entering the quite different inland and freshwater habitats 
would have been forced to acquire new physiological adaptations at 
an accelerated rate. These new adaptations were doubtless accom- 
panied by the physical modifications now found in Schizogenius, 
