206 TREUBIA VOL II, 2—4. 
The stalks of the kontol-ayer 
taken from the Batavia empangs 
which I saw, accordingly proved 
always to have been torn across at 
the end away from the cocoon. 
I did not personally come across 
any other Polychaeta in the Batavia 
empangs than specimens of the 
Fig. 39. Cross-section of Eunice spec. from Eunice species mentioned here. As 
the Batavia empangs. X 71/2. stated in Chapter VI however, 
I once found the fore-intestine of a 
number of Haplochilus panchax (HAM. BUCH.) caught in the 
empangs, filled with Nereidae. In addition the Nereis shown 
in fig. 40 was brought to me by one of my native fishermen 
who told me he had caught the animal in an empang. 
In the Batavia marine fish-ponds there occurs abundantly a 
crab, the well known kepiting (Portunus sp.) which dwells in 
holes in the marginwalls of the ponds. VAN KAMPEN (27) (page 94) 
already describes how this animal is caught. 
The empangs are also inhabited by a number of Decapoda 
Macrura whose general Malay name is “udang”, and which are 
regularly caught and sold for consumption, at least the smaller- 
sized species. 
I can only give a few notes on two Macrura, an Alpheus 
and a Thalassina species. On January 15th 1919 I received the 
animal belonging to an Alpheus species, which is shown in the 
life-size figures 41 and 42 (Plate XXV). The native who brought 
it to me said that it came from an empang near Gagah 
(Division (Afdeeling) Meester Cornelis, District Tjabangbungin). View-X1- 
Also several other natives experienced in the work of the empangs to 
whom I showed the animal told me they had sometimes come across it 
in the empangs. 
In the neighbourhood of Batavia the Malay name of this Alpheus species 
occurring in the empangs is udang plétok or udang tjëték. Both 
pletök and tjéték are anomatopoeical words. The natives that knew the 
animal told me as a matter of fact that it makes a sound that can be represented 
by some such combination as pletök or tjéték. In the Cambridge Natural 
History, Volume IV (78), page 198, it is also mentioned that Alpheidae 
“can emit a sharp cracking sound with the larger claw”. 
The genus Alpheus comprises a great many species which are chiefly, 
met with in tropical seas, and especially in sheets of water or pools on 
coral reefs. The occurrence of on Alpheus species in the empangs conse- 
quently seems to me to be worth mentioning. The reader may be reminded 
