TRYGONIDJS. 53 



and acutely pointed, its length being about 3 that of the disk ; 

 tail equal to 1| or twice the length of the disk. Eyes small ; 

 interorbital space concave. Teeth dental laminae undulated. Fins 

 a distinct cutaneous fold along the lower surface of the tail, com- 

 mencing opposite the base of the spine ; there is likewise a fold 

 along the upper surface of the tail. A strong and long spine, 

 serrated in its last third, is situated at about the commencement of 

 the second quarter of the tail, and anterior to it a row of small 

 spines ; the body otherwise smooth. In some examples a row of 

 tubercles exists along the median line of the back. Colour dull 

 brown superiorly, the edge of the fins black. 



Hub. >eas of India to the Malay Archipelago, and Japan. 



57. (6.) Trygon narnak. 

 Raja uarnak, Forsk. Descr. Anim. p. 18. 

 Trygon uarnak, Miill. $ Henle, Playios. p. 158 $ Day, Fish. India, 



p. 737, pi. cxciv, fig. 1 (see synon.) . 



Sana kah tiriki, Tarn. ; Pulitenke, Tel.; Sankush, Ooriah ; Lek kyouk, 

 Burmese ; Hankoos, Chittagong. 



Disk about as broad as long, snout pointed and rather promi- 

 nent ; tail from three to four times as long as the body. Iris with 

 a well-developed superior flap. Teeth dental laminae undulating. 

 Fins no cutaneous folds on the tail, which is armed with a serrated 

 spine situated about | the length of the disk from the root of the 

 tail. Tubercles vary in different specimens, absent in the very 

 young : in those with a disk of about 6 inches across there are two 

 or three rows of widely separated oval tubercles on either side of 

 the head, internal to the eyes, and meeting on the occiput, from 

 thence towards the scapula is a single row of larger and more 

 widely separated ones. In the middle of the back three large 

 closely approximating scales or tubercles, the centre one heart- 

 shaped, the anterior round, and the posterior almost heart-shaped. 

 In some specimens, of a large size, there are also numerous 

 distant thorns on the tail, which may disappear with age. In 

 specimens with a disk of 3 feet across, the head, back, and sides 

 are covered with smooth, roundish scales, having intermediate 

 smaller ones. Colour varying according to age : up to the period 

 when the breadth of the disk is about 9 inches the body is of a 

 yellowish brown, darkest along the back, and the abdomen white : 

 a short distance beyond the commencement of the tail it is irregu- 

 larly annulated with alternate narrow light brown, and broad or 

 narrow dark brown rings. With increasing age black spots 

 commonly appear on the body, and when it has attained the width 

 of 3 feet across its disk it is light brown or greenish olive, covered 

 with lighter and in some almost white spots, or reticulated with 

 white lines, whilst the anterior extremity of the tail also shows the 

 remains of the rings. The adult is uniformly brownish or greenish 

 olive. Iris golden. Occasionally there are light spots on the 

 posterior portion of the disk. 



