SUNIER: Marine fish-ponds of Batavia. 243 
sometimes called chorion, to express that 
they are supposed to be secondary egg-mem- 
branes i.e. egg-membranes formed by the 
epithelium of the ovarian ovisacs (follicle- 
epithelium). Others however, are of opinion 
that the egg-membranes of the Teleostean 
fishes are formed by the egg-cell itself and 
ought therefore to be looked upon as primary 
egg-membranes, 
The zona radiata derives its name from 
the possession of numerous radially arranged 
very fine canals, which when looked at from 
the surface of the egg-capsule present 
themselves as the fine dots referred to above. 
The zona villosa is absent in many Teleostei. 
Where present it mostly has the function 
of an adhesive organ. 
Now it is well- 
known that in the 
Fig. 17, Egg (with an adhering 
cluster of unripe ova) prepared from 
a fresh ovary of a kepala timah 
(Haplochilus panchax (HAM. BUCH.) ) 
from the Batavia empangs. Adhesive 
threads yet forming a closed layer 
adpressed to the zona radiata or 
inner egg-membrane, X 26. 
Fig. 18. Egg prepared 
from a preserved ovary 
(formol-pondwater 1:19) 
of a kepala timah (Haplo- 
chilus panchax (HAM. 
Bucu.) ) from the Batavia 
empangs. X 15 1/5, 
of the adhesive threads the micropyle of the Haplochilus 
panehax egg is situated. So far however, I have not 
had an opportunity of verifying this. 
Fig. 18 represents an egg prepared from an 
ovarium preserved in formol-pondwater 1:19. In this 
egg the adhesive threads no longer form the closed 
Scombresocidae the villi, of which the zona villosa is 
built up, are modified into long, vermiform crinkled 
threads mostly occurring throughout the entire sur- 
face of the zona radiata, but which are found only 
around the micropyle in Belone, where they are 
shorter (cf. ©. HERTWIG (7°) ). In connection with 
this, and especially since the Scombresocidae are so 
closely related to the Cyprinodontidae, I think 
I ought not only to look upon the long adhesive 
threads of the eggs of Haplochilus panchax likewise 
as modified villi, but also to assume it as probable 
that at the spot round which 
occurs the radiate arrangement 
layer adpressed to the zona radiata, as is the case in 
the egg of fig. 17, prepared from a fresh ovary. Fig. 19. 
In kepala timah eggs spawned a couple of days 
Egg of Haplochilus 
panchax (HAM. BUCH.) 
before, as e.g. the egg of fig. 20, it is visible how found attached to Chae- 
in the spot where the radiate arrangement of the 
tomorpha-filaments from 
the- Batavia empangs. 
adhesive threads was perceived, these threads are x 15, 
