Fishes of the JVestern North Atlantic 4.65 



Doubtful Synonyms: 



Myliobatis ocellatus Kuhl, in van Hasselt, AUg. Konst. en Letterbode Haarlem, i, 1823 (not seen); Bull. Sci. 



Nat. Ferussac, (2) 2, 1824: 90 (Java). 

 Aetohatus ocellatus Fowler, Bull. U.S. nat. Mus., 100 (zj), 1941 : 475 (specimen vi'ithout tail spine, South 



Sea Islands; see discussion, p. 452). 

 Not Myliobatis punctatus Miklucho-Maclay and Macleay, Proc. Linn. Soc. N. S. W., 10, 1886: 675, 676, 



pi. 46, figs. 1-6 (genus Myliobatis because dental plates descr. as of "many longitudinal rows of teeth."). 



Family RHINOPTERIDAE 

 Cow-nosed Rays 



Characters. The subrostral fin, extending forward from the lower surface of the 

 head, is deeply incised in the midline, thus forming two distinct lobes that are, however, 

 continuous with each other basally. The anterior contour of the cranium is moderately 

 concave, so that the front of the head is definitely bilobed in some species though hardly 

 so in others. Floor and roof of mouth without fleshy papillae. Pelvis strongly arched, 

 with median process directed forward. Posterior face of hyoid arch and each face of 

 first to fourth gill arches, as well as anterior face of fifth gill arch with a series of narrow 

 and close-set transverse folds, succeeded inward by about half as many shorter and 

 broader folds; inner edge of each gill arch with about 5—6 much larger fleshy papillae 

 (Fig. 80). Characters otherwise as in the Myliobatidae (p. 433). 



Remarks. The distinctions between the Cow-nosed Rays (Rhinopteridae) and the 

 Eagle Rays (Myliobatidae) are so slight that some recent authors unite the two groups 

 in a single family,* but others regard them as distinct subfamilies'' or families.* The 

 latter course is followed here. 



Developmental Stages. Development is ovoviviparous. After the yolk is absorbed 

 the embryos are nourished by secretions that are poured out by the villi with which the 

 inner wall of the uterus is densely clothed and that are described as giving off a red 

 extract in formalin or in alcohol.'* 



Genera. The various representatives of the group from different parts of the world 

 resemble one another so closely that they are grouped by common consent in the single 

 genus, Rhinoptera Cuvier 1829. 



Genus Rhinoptera Cuvier 1829^ 



Rhinoptera Cuvier, Regne Anim., 2, 1829: 401; type species, Myliobatis marginata Etienne G. St.-Hilaire 

 (Descr. Egypte, I, 1817,^ pi. 25, figs. 3-4); Isidore G. St.-Hilaire (Descr. Egypte, I, 1827: 334). 

 Eastern Mediterranean. 



1. Rey, Fauna Iberica, Feces, i, 1928: 640, as Myliobatidae; Whitley, Fish. Aust., i, 1940: 220, as Aetobatidae. 



2. Fowler, Bull. U. S. nat. Mus., 100 (zj), 1940: 458, Myliobatinae and Rhinopterinae. 



3. Garman, Mem. Harv. Mus. comp. Zool., 36, 1913: 259, Myliobatidae and Rhinopteridae; Beebe and Tee-Van, 

 Zoologica N. Y., 26, 1941: 273, Aetobatidae and Rhinopteridae. 



4. Described for Rhinoptera bonasus by Coles (BuU. Amer. Mus. nat. Hist., 32, 1913: 32). 



5. The generic name Rhinoptera was proposed by van Hasselt, first as RJienoplera (AUg. Konst. en Letterbode Haarlem, 

 I, 1823: 316, not seen) and a year later as Rhinoptera (BuU. Sci. Nat. Ferrusac, [2] 2, 1824: 90), without a statement 

 as to its distinctive characters, except that it is separable from Cephaloptera. Rhinoptera must therefore date from 

 Cuvier 1829, who first applied it to a recognizable Ray. 



6. According to Isidore Geoffrey St.-Hilaire (Vie, Travaux .... Etienne Geoffrey St.-Hilaire, 1847: 425), the ten 



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