300 Papers from the Marine Biological Laboratory at Tortugas. 



Next, chronologically comes Sloane (1725) whose excellent description 

 of the tail and spines has been quoted on page 274. He adds: 



'Tis commonly thought this long Tail is useful to the Fish as an offensive or defensive 

 Weapon, wherewith it may lash anything offending it. Or to round their prey to strike 



them better They are eatable: the stings are cut off as soon as they are taken, lest 



they should hurt unwary People. 



Euphrasen tells us (1790) that, since the wound made by the sting is 

 followed by pain and swelling, the inhabitants of St. Bartholomew think 

 it poisonous. Forster (Lichtenstein 1844) is the last author to tell us that 

 the stings are poisonous. He writes: 



The hooked stings contain poison, and for this reason, when the fish is caught, the 

 stings are at once extracted by the inhabitants of Otaheite. 



BREEDING HABITS. 



Of the manner of reproduction of the Aetobatids, we have until recently 

 (Coles 1910, 1913) had little definite information. Piso (1658) discourses 

 in general of reproduction in sting rays by the laying of eggs inclosed 

 in horny shells. He ends his long paragraph on this with a few sentences 

 on their stings and poisons and says that chief among such rays is Narinari 

 pinima. However, the connection is not close and the inference not clear. 



The commonly accepted idea is that all the pavement-toothed rays 

 are viviparous. This belief is probably based on the statement made by 

 Gunther, in his "The Study of Fishes" (1880) and also in his article on 

 Rays in the ninth edition of the Encyclopedia Britannica (1886), that all 

 the Myliobatids are viviparous, but that the young differ much from the 

 adult forms. Waite (1901) quotes a letter from W. A. Haswell, in which 

 the latter states that all the Australian Myliobatids are viviparous. The 

 other Beaufort Myliobatid, Rhinoptera bonasus, I have (191 2) proved to be 

 viviparous by obtaining (from a specimen only 24 inches wide) two young, 

 measuring 133/2 by 83^^ inches, rolled up like sheets of paper. Bleeker (1852), 

 by a similar operation on a female Rhinoptera javanica of the East Indies, 

 obtained 2 young, 240'" and 280"' wide. Couch (1862) in his British Fishes, 

 states that M. aguila is oviparous, the eggs being laid in large purses. He 

 figures and describes a young one obtained from such an egg-case; but this 

 must have been a wrong identification. Jordan and Evermann (1896) say 

 that the Myliobatids are ovoviparous, while Smith (1907) afifirms that they 

 are viviparous. 



Thompson (Jordan and Thompson, 1905) has observed that at the 

 Tortugas these fish not infrequently swim in pairs in long straight lines 

 near the surface. Unfortunately the time of year is not stated. This is 

 probably a pairing play preliminary to copulation. As early as 18 10, Risso 

 noted a similar association in the related form Cephaloptera massena of Nice. 

 The male was seen for two days swimming around the net in which the 

 female had been taken, "in order without doubt to search for her," and was 

 finally caught in the same net. Blyth (1861) notes of an Indian sting ray, 

 Trygon inibricatus, that: "This species is so very often brought in pairs to 



