The Spotted Eagle Ray. 301 



the bazar, a male and a female, that I can not help suspecting that it lives 

 in pairs, the two being commonly taken together." 



The question of viviparity or oviparity in Aetohatiis 7iarinari was, how- 

 ever, settled long ago by Klunzinger (1871), who says of the Red Sea Aeto- 

 batus narinari that "the foetus measures 12 centimeters." This fact, however, 

 seems to have been generally overlooked. The method of delivery of the 

 young was observed by Mr. Coles in 1910, while fishing at Cape Lookout. 

 After noting that these rays swim near the surface of the water in large 

 schools (one being estimated by him. to contain hundreds of individuals) 

 he goes on to state as follows: 



For a number of years my crew and other deep-sea fishermen have been telling me that 

 in giving birth to its young the female ray leaps high in the air as each young is born, but 

 as this leaping seemed so unnecessary I had questioned their tales. However, on about 

 July 15, 1910, I was suddenly called on deck by two of my crew and then I saw a large female 

 Aetobaius narinari leaping high in the air and falling back into the water within 20 fathoms 

 of the yacht. After she had thus leaped several times, I distinctly saw a young one about 

 6 or 8 inches wide thrown from the body; and after she had again leaped several times 

 without result, another young one was born, and my men told me that two had been born 

 before I came on deck. 



While at anchor in the channel off Boca Grande Cay, Florida, in June 

 19 1 3, numbers of leaping spotted eagle rays were seen, some quite near the 

 boat. I thought that one gave birth to a young one while leaping, but 

 could not be sure. 



The explanation of the leaping is probably to be found in the fact that 

 the sudden leap throws the viscera downwards and, aided by the simultaneous 

 contraction of the muscles of the anterior part of the uterus, expels the 

 young. The principle is the same as that by which we drive the last traces 

 of a liquid from an inverted bottle by sudden jerks. Corroborative of this is 

 the fact that whenever a ray is suspended there is a great tendency for the 

 cloacal parts to protrude. 



As to how the foetuses are nourished in utero nothing definite was known 

 until Coles published his 1913 paper. Coles states that the uterus of his 

 specimen shown in figures 9, 10, and 11, plate v, was densely lined with large 

 villi 25 mm. in length. These villi secrete a milk on which the embryos are 

 nourished by absorption through the external gills, and later by intake 

 through the spiracles, as the present writer has shown for the other Beaufort 

 rays, Rhinoptera honasus, Pteroplatea maclura, and Dasyatis say (Gudger, 

 1910, 1912A, 1913). 



However, as early as 1876 Trois had microscopically studied the uterine 

 structures of the related Myliohatis noctula of the Mediterranean. He found 

 the walls of its uterus so crowded with villi that the mucosa could not be seen; 

 the number of these, however, decreased towards the mouth of the uterus, 

 which was plicated. These thread-like organs were permeated with blood- 

 vessels, thus enormously increasing the vascularized surface of the uterus. 

 The young were enwrapped by these villi, which, being of great numbers, 

 acted as a feeding organ for the embryos, establishing thus an "efficacious 



