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. iiarnak can be distinguished — 



Var. 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 Forskal says in 

 his original description ' ' tota maculata ' ' {Descr. Anim., p. i8, No. i6b, 1775). 



Var. b 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 ; and Faun. Brit. Ind., Fishes, vol. i, p. 53), had seen the true T. uarnak, 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. uarnak by several authors, notably by Müller and 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 HughH on a muddy bottom. 



Trygon gerrardii, Gray. 

 T. gerrardi, Gz-m^Äßf , 0/). azî., p. 474. 

 T. uarnak, Day, Fishes of India, vol. ii, pi. cxciv, fig. i. 



To describe this species it is onl5^ necessary to indicate the points in which it 

 differs from T. uarnak. 



Size moderate (largest specimen 67 5 cm. across the disk). 



Disk shaped and proportioned much as in the yoimg of T. uarnak. 



