Jordan and Evermann. — Fis/ics of North America. 65 



P?a<)/)7iiHa earospcraio, Jordan & Gilbert, Proc. U. S. Nat. Mus., 1880,32, San Diego. (Tyjje 



No. 35050.) 

 Zapteryx exasperatiis, Jordan &. Gilbert, Proc. U. S. Nat. Mus., 1880, 53. 

 TrygoHorhina alveata, Garman, Bull. Mus. Comp. Zool., 1880, 169, San Diego, 

 Synhina exasperata, Garman, Proc. U. S. Nat. Mus., 1880, 521. 

 Shinobatits exasperalus, Jordan & Gilbert, Synopsis, 6.1, 1883. 



89. ZAPTERYX XYSTER, Jordan & Evermann, new species. 



Disk somewhat broader than long, its length slightly greater than that 

 of tail. Coloration similar to that of Z. exasperatus, including the large 

 black blotch on posterior angle of pectoral below ; upper side of disk with 

 several round yellowish spots as large as pupil, each spot ocellated with 

 blackish ; a very distinct spot on each side of shoulder; a second on pec- 

 toral fin near posterior angle ; a third midway between latter and median 

 line of back; several fainter spots on back anteriorly. Spines and 

 prickles above as in Z. exasperatus, but entire lower surface covered with 

 fine shagreen, this perhaps a sexual character. L. 22 inches. Two female 

 specimens (Museum Yale University), collected by Prof. Frank H. Bradley 

 at Panama in 1866. {^varrjp, a scraper.) 

 Syirhi)M excuiperata, Jordan & Gilbert, Proc. U. S. Nat. Mus., 1882, 621. 



47. PLATYRHINOIDIS, Garman. 



Phlyrhinoiilh, Garman, Proc. U. S. Nat. Mus., 1880, 522, (Iriseriata). 



Disk broad, flat, and rounded, the tail moderate, depressed ; dorsals 

 posterior; middle line of back and edges of pectorals and tail with stout 

 spines ; skin covered with fine shagreen as in Ehinoiatus ; labial fold well 

 developed; nasal valves not reaching the mouth, the posterior lobe rudi- 

 mentary. One species, with the general form of a ray and the color and 

 appearance of Bhhiobatus, like which genus, it is viviparous. (PJitty- 

 rhina, or Discobatus, an Asiatic genus of Bajidce, which species it resem- 

 bles in form; iUog, like; Platyrhina from liXarvg, broad; [jIv, snout.) 



90. PLATYRHINOIDIS TRISERIATUS, (Jordan & Gilbert). 

 Disk broad, ovate, broader than long; snout very bluntly rounded, not 

 projecting; the angle formed by the pectorals anteriorly very obtuse; 

 anterior outline of the pectorals slightly convex, not undulated. Tail very 

 stout, much longer than the disk, its edges with a broad fold, broader than 

 in Z. exasperatus ; pectoral fins extending almost to the tip of the snout; 

 rostral ridges wide apart, strongly converging forward, inclosing a trian- 

 gular area. Eyes small, wide apart; the broad spiracles close behind 

 them. Caudal fin well developed above and below; dorsals similar, 

 their posterior free margins very convex ; first dorsal well backward, 

 its origin nearer root of caudal than ventrals. Mouth broad, its width 

 nearly equal to its distance from tip of snout, a deep crease passing around 

 it behind, in front of which the lower lip has 3 folds of skin ; upper 

 Up not developed, a fold of skin passing from the angle of the mouth on 

 either side to the inner angle of the nostrils, thence straight across, 

 inclosing a depressed, trapezoidal / \ shaped area, bounded below by 

 the curved outline of the upper jaw: in this are 3 cross folds of skin. 



!•'. N. A. 6 



