24 Memoirs of the Indian Museum. [VoL. II, 
not disappear abruptly as the bare area is reached, but gradually become smaller 
and form no definite outline to the area they cover. 
Mouth large. The jaws are almost straight. The teeth are large, usually more or less 
deeply tinged with brown in fresh specimens ; in the back of the jaws, where 
they are not worn, each has two distinct transverse ridges, a secondary shorter 
one running parallel to the median ridge and in front of it. There are nor- 
mally four processes on the floor of the mouth, subequal in size, the two lateral 
ones being only smaller than the two median, and situated at about an equal dis- 
tance apart. A somewhat similar process projects into the mouth from the cuta- 
neous fold which covers the inner base of the teeth of the lower jaw ; the fold 
which hangs down from the roof of the mouth is somewhat coarsely digitate. 
Two colour varieties of T. uavnak can be distinguished — 
\^ar. a. Anterior part of the disk spotted in the adult, the spots combining 
on the posterior part into irregular blotches or figures. 
Var. h. The whole of the dorsal surface of the disk covered in the adult with 
an irregular network of dark lines, often with dark spots or streaks 
in the centre of the meshes. 
Var. a must be considered the typical form of the species as Forskâl says in 
his original description ‘ ‘ tota maculata ” {Descr. Anim., p. i8, No. i66, 1775 )- 
Var. h may be identical with T. undulatus, Bleeker. According to Blyth 
it is identical with McClelland’s T. variegatus, but I have not seen any specimen on 
which the markings were so scanty and so open as they are represented in the figures 
published by the latter author {cf. Blyth, Journ. Asiat. Soc. Bengal, xxix, p. 43, and 
McClelland, Calc. Journ. Nat. Hist.^ i, p. 66, pi. 2, fig. 2). 
Day, judging from his description {Malabar Fishes, p. 277; Fishes of India, vol. 
ii. P- 735 i a-iid Faun. Brit. Ind., Fishes, vol. i, p. 53), had seen the true T. iiarnak, but 
unfortunately his figure in the Fishes of India (pi. cxciv, fig. i) represents not this 
species but T. gerrardii, a smaller and otherwise different species which has been con- 
fused with T. by several authors, notably by Müllerand Henle (“ Plagiosto- 
men,’ ’ p. 159, vars. i and 3). 
I have been able to examine a very large series (some hundred specimens) of this 
species, representing every stage between the unborn young and the adult over five 
feet in diameter. Specimens have been taken practically every trip by the ‘ ‘ Golden 
Crown,” but Dr. Jenkins tells me that large individuals are particularly abundant 
in about 30 fathoms of water off the mouth of the river Hughli on a muddy bottom. 
Trygon gerrardii. Gray. 
T. gerrardi, Günther , op. cit., p. 474. 
T. uamak. Day, Fishes of India, vol. ii, pi. cxciv, fig. 1. 
To describe this species it is only necessary to indicate the points in which it 
differs from T. iiarnak. 
Size moderate (largest specimen 67 5 cm. across the disk). 
Disk shaped and proportioned much as in the young of T . uavnak. 
