294 Papers from the Marine Biological Laboratory at Tortiigas. 



upper jaw is marked off pretty accurately by these grooves, rarely extending 

 out beyond them more than a mere fraction of an inch. The lines formed 

 by these depressions may be seen if looked for on the smaller specimens, but 

 on the large jaw-plate are very plain, being probably one thirty-second of an 

 inch deep. These points have never been noted before. Text-figure 15 is 

 made from the upper jaw of the largest Florida specimen. In front is 

 shown the worn area, and extending backward on each side in the region of 

 the bends of the teeth are faintly stippled areas marking off this depression. 

 From a consideration of the data above it will be seen that in the teeth, 

 as in all other structures, the spotted eagle ray is evidently subject to very 

 great variations. 



DORSAL SENSORY PORE SYSTEM. 



There is now to be described a system of sensory pores on the dorsum of 

 A. narinari which has never been noted before, and which I myself over- 



Text-fig. 16. Dorsal sensory pore system of A. narinari from Key West, 



1913 (semidiagrammatic). 



looked on Beaufort specimens, but found on the frozen Florida rays and 

 also on the live one. 



Beginning back of and between the spiracles and running backward on 

 each side of the median line are fanciful figures made of lines in the flesh, 

 each ending in a black pore. Some distance forward of a line connecting 

 the points of the pectorals, these bands of pores diverge to form two back- 

 wardly extending and diverging lobes. However, extending backward 

 between these, on either side of the spinal column, is a band of pores similar 

 to the anterior ones. These widen out over the soft part of the back, 

 dorsal to the abdomen, and further back they nearly converge just in front 



