1916.) B.SuNDARA Raj: Freshwater Fish of Madras. 289 
34); but when the tail is detached from the yolk-sac the embryo 
changes its orientation by the agitation of its tail (fig. 35). The 
fry on hatching (fig. 36) measure about 2°25 mm. long and are 
not quite so helpless as the larvae of Ophiocephalus, Etroplus, etc., 
but are able to feed and swim. The parents do not appear to 
guard them after hatching. The eggs and fry of this species are 
very difficult to rear when removed from their natural surround- 
ings. 
Uses.—G. giuris grows to a foot and a half in length and 
fetches a high price in the local market when large. 
Gobius (Oxyurichthys)! striatus (Day). 
(Pip xxixw fips. 37-38). 
Tamil—Kundalam. 
Habitat and Habits —Not uncommon in ponds, rivers and in 
the backwater. 
It is a sluggish fish, chiefly nocturnal in habits, and frequents 
sandy shallows, where it is fond of lying half buried during the 
day time. Its movements are for the most part confined to the 
bottom, but it swims occasionally in a feeble clumsy manner, 
swaying and rolling irregularly. 
This species breeds from October to November. Mr. Wilson 
of the Madras Fisheries obtained a nest of this fish with eggs in 
an advanced condition. Figs. 37 and 38 are copies of his figures 
reproduced by kind permission. The eggsclosely resemble those of 
G. giuris and Jike them are attached to the under surface of de- 
mersed stones, tiles, etc., by means of a gelatinous stolon. 
Rhyncobdella aculeata (Bloch). 
Tamil—A: val. 
Fairly common in fresh and ercieh water. 
In an aquarium R. aculeata habitually conceals itself by day 
in the bottom sand or mud, with just the snout and at times the 
whole head projecting above the sand for respiration; even this 
is withdrawn at the least disturbance. At night however it 
emerges to feed. The pointed snout, the weak sight, the conical 
head, the absence of the ventral and the poorly developed pectoral 
fins are obvious adaptations to the burrowing habits of this fish. 
The dorsal spines are organs of defence, while the trilobed proboscis 
is evidently an organ of touch. ‘The fish lives a long time out of 
water, and is known to withstand periods of drought by burrowing 
in the bottom mud of ponds and streams.* ‘‘ It becomes drowned 
in water if unable to feESs the surface, as it apparently requires 
to respire air directly.” es 
Uses.—It is moderately esteemed as food. 

lL Max Weber, Die Fische der bier: Expedition, p- 475: 
: 2 Day, Freshwater Fishes and Fisheries of India and Burma, p. 28 (1873). 
3 Fauna of Brit. India, Fishes, Il, p. 332. 
