FISHES OK NEW YOKK "'.'! 



Suborder MASTICURA 



Whip-tailed Rays 

 Family DASYATIDAH: 



Stitiy Rays 



Gouus DASYATIS Rafinesque 



Disk usually broader thau long; pectoral fins united in front 

 to form the tip of the snout; tail very slender and elongate, fin- 

 less, but often with one or two membranous folds, and with a 

 strong serrated spine near its base; skin rarely smooth, usually 

 more or less spinons or prickly, tail with numerous small spines 

 in some species; mouth small; teeth small, paved, usually more 

 or less pointed or tubercular; a few papillae, usually in the 

 mouth behind the lower jaw; nostrils close together; nasal 

 valves forming a rectangular flap, which is joined to the upper 

 jaw by a narrow frenum; spiracles large, placed close behind 

 the eyes. Ovoviviparous. 



28 Dasyatis centrura (Mil chill) 

 Common Xthiy Rai/ 



cintriini MITCI-IILL, Trans. Lit. & rhil. Soc. N. Y. I. 479, 1815. 

 ]'<iNtin<i<-(i ini.isti.ita STOKER, Hist. Fish. Mass. 268, pi. XXXIX, fig. 3, 1807. 

 -l)a*i,biiti>< centrum JORDAN & GILBERT, Bull. 1G, U. S. Nat. Mus. 67, 1SS3. 



(From Garnian) 



Trillion haxtatH. GUXTHER, Cat. Fish. Brit. Mus. VIII. 476, 1870. 

 Daximtix centrum JORDAN & EVER/MANX. Bull. 47, U. S. Nat. Mus. 83, 189G; 

 SMITH, Bull. U. S. F. C. XVII, 90, 1S9S. 



Disk quadrangular, about one fourth wider than long; ante- 

 rior margins sinuous, concave opposite the eyes, convex toward 

 the slightly protuberant snout and rounded over angles; pos- 

 terior straighter, very little convex; hinder angles blunt; ven- 

 irals truncate, with rounded angles; tail more than twice as 

 long as the body, much compressed, rounded above, with keel 

 or cutaneous expansion below, with one or more strong serrated 

 spines at the termination of the anterior fifth of its length, 

 rough on all sides w r ith spines or tubercles. Till half grown the 

 young are naked; as they approach maturity broad stellate 

 based, conical pointed, irregularly place,! bucklers appear on the 

 middle of the hinder part of the back and on the top and sides 



