Fishes of the Western North Atlantic 9 1 



Spiracles separated from eyes by a definite interspace, their posterior margins either 

 smooth or with papillae. Midline of back a little posterior to level of spiracles with 

 either a pair of conspicuous mucous pores side by side or a group of 5-9. Nostrils 

 transverse to slightly oblique, much closer to mouth than to tip of snout, longer than 

 space between them. Nasal curtain subquadrangular, considerably broader than long, 

 concealing all but outer ends of nasal apertures and extending nearly or quite to upper 

 jaw; free posterior margin of nasal curtain smooth, more or less sinuous, or with the 

 midsector projecting somewhat. Mouth only slightly protractile, if at all, without labial 

 cartilages and therefore widely distensible; the lateral articulations between upper and 

 lower jaw cartilages small in area and hardly interlocking; skin at corners of mouth 

 loose, with a well marked furrow extending rearward for some distance;*' roof of mouth 

 without digitate lobes anterior to the main transverse fold, the latter smooth-edged, 

 of nearly uniform breadth throughout its length. Tooth bands not reaching to apparent 

 corners of mouth when latter is closed, the integument bearing them rather firmly 

 attached to the narrow jaw cartilages. Teeth with one sharp conical cusp, arranged in 

 quincunx close together; up to about 64 series in each jaw, with 3 or 4 to 6 or 7 rows 

 in function simultaneously. Two rostral cartilages, each a flexible unbranched vertical 

 plate, the pair well separated next to the cranium but approximating each other and 

 flattened dorsoventrally toward tip of snout, where they and the neighboring antorbital 

 cartilages are interconnected by sheets of firm fibrous tissue.** Characters otherwise 

 those of the family. 



Size. This genus includes the largest of Atlantic Electric Rays (p. 85). 



Developmental Stages. It has been known for more than a century that the inner 

 wall of the uterus in gravid females of some species is set with vascular villi, while in 

 that of others it bears a series of longitudinal folds only.*' The later embryonic stages 

 of Torpedo are of special interest because the anterior limits of the pectorals in some 

 are marked by a well marked notch on either margin of the disc until the young are 

 nearly ready for birth (Fig. 23). These notches are described and figured as persisting 

 for a time after birth in three species.*" 



Habitat and Range. In the Atlantic the genus Torpedo occurs in water of only a 



43. The degree to which the jaws may protrude and the width to which the mouth may gape when spread to its widest 

 (not yet known), can be determined only from observation on living specimens when they are feeding. 



44. Carman's illustrations (Mem. Harv. Mus. comp. Zool., 36, 191 3: pi- 67, figs, i, 2) show the rostral cartilages of 

 Torpedo marmorata as rounded bars branched at the tips. But those on his original dissection are as described above. 

 Also, the margin of the antorbital cartilages are not as complexly dissected as they are represented in his illu- 

 strations. 



45. Davy, Philos. Trans., 1834: 547; Muller, Ober den glatten Hai (1839-1840), 1842: 55. For a recent account of 

 the uterine wall of Torpedo torpedo (Linnaeus) 1758, with photographs, see Ranzi (Publ. Staz. zool. Napoli, Jj, 

 1934: 359); also see Needham (Biochem. Morphogen., 1942: pi. i, fig. 7). 



46. Small European specimens of Torpedo nobiliana are so pictured by Bonaparte (Icon. Faun. Ital., J, 1835: pi. not 

 numbered), by Rey (Fauna Iberica, Feces, r, 1928: 524, fig. 16S), and by Fowler (Bull. Amer. Mus. nat. Hist., 

 JO [i], 1936: 120, fig. 48), as are the New Zealand T.fairchildi (as Torpedo fusca by Parker, Trans. Proc. N. Z. 

 Inst., 16, 1884: 283, pi. 22, fig. i) and T. nobiliana of the western Atlantic by Carman (Mem. Harv. Mus. comp. 

 Zool., 36, 1913: pi. 61, figs. 4-5). Kaempfer's early illustrations (Amoenitatum Exoticorum, 1712: pi. to face 

 p. 511, figs. A, B) of T. sinus-persicus Olfers 1831 of the Persian Culf, Red Sea, and Indian Ocean, though crude, 

 also show the notched pectorals. 



