1966 ] 
Whitekead — Halocoryza 
225 
Puerto Rican locality is in the British Museum (Natural History). 
Both known localities are coastal, and arenaria is probably an 
inhabitant of the sea-shore as seems characteristic for the genus. 
Darlington (1939) recorded his unique specimen as having been 
taken “. . . under a deeply buried log on the sandy ocean beach . . .” 
He recognized many of its essential features and {in litt.) suggested 
to me its probable relationship to Halocoryza. 
DISCUSSION 
As noted in the generic description, Old World species of Halo- 
coryza differ from New World species in at least the following 
respects: pronotum lacking submedian carinae; sixth frontal carina 
broken in front of eye; and apex of median lobe of male genitalia 
not produced, the basal diameter more than 0.65 ventral length. 
Once the genus is better known, it may be desirable to place the 
American species in a separate subgenus. 
Mr. Jacques Negre {in litt.) has confirmed my impression that 
Jeannel’s (1946) description and figures of maindroni are very in- 
accurate and misleading. The type specimen and other examples in 
the Museum National d’Historie Naturelle, Paris (including Mada- 
gascar material) resemble and may be conspecific with the Arabian 
specimen of maindroni seen by me, and are generally in accord with 
Alluaud’s (1919) original description and figures. Vinson (1956) 
described II. jeanneli from Mauritius in comparison with Jeannel’s 
interpretation of maindroni ; his study seems accurate in detail, and 
may portray the true maindroni. I suspect that these species may be 
identical, since they should have a high tolerance to salinity and 
desiccation and hence be able to disperse easily over sea barriers. 
However, it is quite possible that the populations on both Mauritius 
and Madagascar are endemics distinct from the mainland populations. 
If they do disperse readily, the species of Halocoryza should be 
widespread. However, the scanty available information indicates 
that the present day distribution, though equatorial, is apparently not 
pantropical. Only acapulcana is so far known from continental North 
America, but arenaria may yet be found on the Atlantic coast. The 
African species ( maindroni t jeanneli ) are found along the east coast 
north to Arabia (Britton, 1948) and on islands in the Indian Ocean. 
Although no South American or West African species are known, 
at least a past occurrence in both areas must be assumed to account 
for the present distribution of the genus. 
Available evidence suggests dispersal from Africa, the most prob- 
able center of origin. The Atlantic was probably crossed by “rafting” 
