534 Memoir Sears Foundation for Marine Research 



use being made of the wing-like pectorals, which, on the contrary, are the effective swim 

 ming organs of skates and rays.* 

 Only one family is known. 



Family SQ UA TINIDAE 



Characters. Snout very broad and short; eyes dorsal, without nictitating membranes: 

 spiracles large; nostrils terminal, entirely separate from mouth, their anterior margin; 

 with barbels which are variously lobed; gill openings lateral, but extending onto lowei 

 surface; mouth protrusible at corners with well developed labial cartilages, nearly ter- 

 minal but separated from front of snout by a deep transverse furrow which is edged by £ 

 thin, variously-lobed fold of skin; lower jaw with deep labial furrows near corners; teetl 

 numerous, similar in the 2 jaws, with single thorn-like cusp on broad base, 3 or 4 series 

 functional; caudal axis not raised at all above main axis of trunk; lower lobe of cauda. 

 longer than upper. Development ovoviviparous ; embryo with very large yolk sac." 



Genera. Only one genus is known. 



Genus Squatina Risso, 1 8 10 



Squatina Risso, Ichthyol. Nice, 1810: 45; type species, Squatina vulgaris Risso, equals Squalus squatim 

 Linnaeus, 1758.^' 



Generic synonyms: 



Rhino SchaefiFer, Epist. Stud. Ichthyol., 1760: 20; Klein, Neuer Schauplatz, 2, 1776: 587; Walbaum, P 

 Artedi Gen. Pise. Emend. Ichthyol., 1792: 580, not available;'^ not Rhina Bloch and Schneider, Syst. Ich- 

 thyol., 1 801: 352; Cuvier, Regne Anim., 2, 1 81 7: 133; Muller and Henle, Plagiost., 1 841: lio; a ra) 

 which was subsequently named Rhamfhobatis by Gill, Ann. N. Y. Lye, 7, 1 862: 408. 



Generic Characters. Head broadly rounded, with wing-like lateral expansions; 

 spiracles behind eyes and at the same level as the latter; lips with well developed support- 

 ing cartilages, widely protrusible at corners of mouth but not centrally; anterior margins 

 of pectorals expanded anteriorly as narrow shoulder-like extensions, lying below the 

 lateral expansions of the sides of the head, partly concealed by the latter, and more or less 

 overlapping the pel vies rearward; pel vies originating anterior to posterior corners of pec- 

 torals; dorsals much smaller than pectorals or pelvics; caudal triangular, its posterior con- 



9. For a recent discussion of the affinities of the suborder, based chiefly on the skull, see Holmgren (Acta Zool., 22. 

 1941 : 79). They are classed (as Angeliformes) among the skates and rays by Le Danois (Rev. des Trav. Peches 

 Marit., t^, 1945: 67) because of the nature of their vertebral calcifications. 



10. Garman, Mem. Harv. Mus. comp. Zool., 56, 1913 : pi. 61, fig. 9— 1 1. 



11. The name Squatina was first proposed by Valmont (Diet. Rais. Univ. Hist. Nat., /, 1768: 117). But by ruling 

 of the International Commission on Zoological Nomenclature (Smithson. Misc. Coll., 75 [3], 1925: 27, Opinion 

 89) his names are not taken into consideration. It was next mentioned by A. M. C. Dumeril (Zool. Anal., 1806: 

 102), but without inclusion of any particular species, so that, as a generic name, it must date from Risso, 1810. 



I 2. Schaeffer did not include any species in his Rhina; and the generic names proposed by Klein and republished by 

 Walbaum are not to be taken into account, according to Opinions 21 and 89 of the International Commission 

 on Zoological Nomenclature (Opinions Rendered, Smithson. Publ., No. 1938, 1910: 51; Smithson. Misc. 

 Coll., 7 [3], 1925: 27). 



