SUNIER: Marine fish-ponds of Batavia. 207 
here of the regeneratio inversa observed in A/pheus. If the larger claw is 
severed the smaller claw develops into the inverse image of the larger claw 
that was lost, whilst in the place where the lost one had been there 
develops a new claw which is the inverse image of the original smaller claw. 
The Thalassina species mentioned above, and represented in fig. 43 
(Plate XXV), occurs properly speaking, not in the empangs, but between 
them, and as a matter of fact in the walls separating the ponds. 
At Batavia and especially between the empangs of Luar Batang, one 
sees rising above those walls here and there little chimneys consisting of 
the same kind of soil of which the walls themselves are composed. These 
chimneys have the shape of low truncated cones whose top plane exhibits 
an orifice which is not purely circular but somewhat oval shaped. Below 
follow the dimensions in centimetres of three of these little chimneys. 
Diameter of Height Diameter of Diameters of the oval aperture 
ground-plane top plane in the top plane 
19 10 12 2.3 2.5 
23 12 14 45—5 
34 15 17 5 —6 
From these chimneys a 
channel leads down into the 
eround. The natives who are 
accustomed to work and dig „” 
in the empangs say that this 
channel down below divides into 
several galleries and each of 
these is said to lead to a separate 
chimney. Now it is in these 
galleriesthatthe 7halassinaspecies 
represented in fig. 43 (Plate XXV) 
lives and burrows; at Batavia its 
Malay name is udang tanah. 
A few specimens of this udang 
tanah venturing out of their 
chimneys were captured by my 
fishermen. 
It appears that the galleries 
never debouch in the empangs, 
Newer did], nor any of the 
natives who are at home in 
the empangs and of whom | 
enquired, ever find a 7halassina Fig. 44, Gammarid occurring regularly and numer- 
. ously among the algal masses and higher submerged 
in the ponds themselves. aquatic plants in the Batavia empangs. X 16. 
