206 



ON A FIDDLER (TRYGONORHINA FASCIATA), WITH 

 ABNORMAL PECTORAL FINS. 



By Jas. p. Hill, Demonstrator of Biology, in the 

 University of Sydney. 



(Plate XX.) 



Some little time ago there came into my possession through the 

 kindness of Mr. J. Has tie, Broken Bay, N.S.W., a specimen of 

 the Fiddler-ray {Trygonorhinafasciata), with markedly abnormal 

 pectoral fins. The specimen presented so peculiar and striking 

 an appearance that it was picked out by the fishermen when 

 looking over the contents of their net after a haul and kept as a 

 curiosity. On describing the specimen to my friend. Prof. G. B. 

 Howes, he referred me to a note"^ by Dr. Traquair on an abnormal 

 Thornback {Raia clavata). Dr. Traquair very kindly furnished 

 me with a copy of his note, and I am now enabled to give a 

 description of this specimen. 



The Fiddler in question is a young male, measuring 2 6 '9 cm. in 

 length, and 11-2 cm. across the broadest part of the pectoral fins. 



From the illustration accompanying this note it will be seen 

 that the pectoral fins are markedly abnormal, and give the fish a 

 very striking appearance. On each side the anterior portion of 

 each pectoral fin is separated by a wide and deep notch from the 

 head. The notch on the left side is, as in Dr. Traquair's Thorn- 

 back, deeper than that on the right, causing the animal to have a 

 very asymmetrical appearance. On the right side the notch 

 extends backwards from the anterior end of the pectoral fin for a 

 distance of 3 cm., and terminates almost on a level with the 

 posterior border of the spiracular cleft. On the left side, however, 

 the notch extends back for a distance of 4*5 cm., terminating at 



* Note on an abnormally developed Thornback {Raia clavata), Ann. of 

 Scottish Nat. Hist. Jan., 1892. 



