SUNIER: Marine fish-ponds of Batavia. 163 
show exactly the same type as the sluice-gates of the marine fish-ponds 
of Arcachon. This is immediately apparent on a comparison of our photo 
no. 1 (Plate VI) and the schematic figures in VAN SPALL (?) and in 
DE JAAGER and VAN LAWICK VAN PABST (!7), with the illustrations in the text 
no. 1—3 and the photos 1—6 on plates II — IV in HORNELL (?'). Even the net 
(“la manche”) mentioned by HORNELL at the bottom of page 8 can be found 
again in the little empang sluice-gates, under the Javanese name of “ta da h”, 
§ 2, The Empangs of Batavia. 
The data relative to the biology of the empangs which are now at my 
disposal, I have collected exclusively in the marine fish-ponds in the neighbour- 
hood of Batavia. 
The territory of the properly so called Batavian sea-fish-ponds stretches 
from Slingerland or Oesterbank in the East, as far as slightly to the East of 
Muara Angke as their Western limit (cf. Map I). When we demarcate this 
territory to the North by the coast-line of the Java Sea (Bay of Batavia) ; to the 
East by a line running from the wayside station Antjol to the sea, at right 
angles with the railway embankment; to the South by the Trekvaart as far as 
Pasar Ikan, and further by the Groningsche Weg as far as the Muara 
Karang, then by the Muara Karang in a southerly direction as far as 
Telokgong; next to the West by the Western branch of the Krukut 
Draining Canal towards the North until the Kali Angke is reached, and 
finally by this river down to the sea, then the area of the territory thus 
defined, covers, according to the Cadastral Survey Office (Hoofdbureau van 
het Kadaster), about 1195 hectares or 2950 acres. Within these boundaries 
the fish-ponds proper, together with the embankments and walls separating 
the ponds, are stated by the Cadastral Survey Office to occupy circa 730 
hectares or 1800 acres. | have myself calculated this area by transferring 
the fishponds with the embankments and walls between them from the 
Topographical Service !) map (1:50.000, brought down to date, 1 May 1918) 
on to millimetrepaper, and thus arrive at an area of only 687 hectares or 
1700 acres. Including two strips of land, some 50 M. broad, stretching 
north between the ponds near Pekulitan, I arrrive at about 695 or not 
yet 700 hectares = + 1720 acres). 
I have no means of determining with accuracy what part of these 700 
hectares represents the real surface of the ponds properly speaking, and how 
much goes to the embankments and walls in between, for it is recognized 
that the Topographical Service maps represent these embankments and walls 
too broad. | think, however, I am not far wrong in estimating the water-surface 
at not less than */, of these 700 hectares, the remaining '/; being taken up by 
walls and embankments, VAN BREEMEN’s estimate (5°) (p. 324) putting the water- 
surface of the fish-ponds comprised between the Muara Karang and the Kali 
Sunter at 500 hectares or 1230 acres, therefore strikes me as fairly accurate, 
') Topographical Service = Topographische Dienst. 
