17. TBYGON. 481 



sively covered with small tubercles which do not louch one another. 

 Minute tubercles on the tail. Very young individuals are probably 

 entirely naked. Three papillae at the bottom of the mouth behind 

 the teeth. Dental laminae much undulated. Coloration uniform. 

 American parts of the tropical Atlantic ; Sydney. 



a. Fine specimen (disk 15 inches long). South America. Presented 



by Sir R. Schomburgk. 

 6. Young. Island of Grenada. Purchased of Mr. Higgins. 



c. Young. Lake Champlain. Purchased of M. Parzudaki. 



d. Young. United States. 



e. Half-grown. 



/. Adult (disk 20 inches long). Sydney. Purchased of ISlr. Gerrard. 



20. Trygon imbricata. 



Raja imbricata, Bl. Schn. p. oGG. 



Trygon imbricata, Mull. ^- Henle, p. 164 ; Dumhnl, Elasmobr. p. (306. 



Tail scarcely as long as the body, with very low cutaneous folds, 

 the upper a little higher than the lower. Disk as long as broad. 

 The margins of the snout form a right angle. Two appendages at 

 the bottom of the mouth, behind the teeth. Small tubercles on the 

 nape and back ; they form a rhombic figure on the back of adults. A 

 series of thorns in the median line of the back and on the shoulder. 

 A band of scale-like tubercles on the tail, from its root to the spine, 

 so arranged that pairs of small ones alternate with single larger ones. 

 {M. 4- H.) 



Indian seas. 



21. Trygon zugei. 



Trvgon zugei. Mull. Sf Henle, p. 1(35, pi. 53 ; ISchlcg. Faun. Japan 

 Pinss. p. 309 ; Cant. Mai. Fish. p. 426 ; Bleek. Verh. Bat Gen. xxiv. 

 Placj. p. 68 ; Dum^ril, Elasmobr. p. 606. 



crozieri, Blijth, Journ. As. Soc. Benrj. 1860, p. 45. 



Tail with a distinct cutaneous fold above and below, one-half 

 longer than, or twice as long as, the disk. Snout conskhrahhj pro- 

 duced and pointed. Entirely smooth or with a series of pointed 

 tubercles in the median line of the back to the caudal s])ine. Dental 

 laminae much undulated. Uniform bi'own above. 



Japanese and Indian seas. 



a. Half-grown. Japan. Purchased of Mr. Jamrach. 

 h-c. Young: skins. From Chinese insect-boxes. Presented by J. 

 Brenchley, Esq. 



d. Half-grown. East-Indian archipelago. From Dr. lileekei's 



Collection. 



e. Young: skin. Pinang. From Dr. Cantor's Collection, 

 f^. Young, in bad state. From Dr. Cantor's Collection. 



h. Young, in bad state. Madras. Presented by Capt. Mitchell. 



VOL. vi;i. 2 i 



