Jordan and Rvermann. Pishes of North America. &7 



of each pectoral is somewhat concave. Color brownish olive, finely 

 unruled with grayish, and finely speckled ; anterior edge of disk with 

 half spots of paler; tail with 4 dark blotches above, forming half rings. 

 (Caudal spine wanting in all the specimens examined.) Long Island 

 to Brazil ; not uncommon on the Carolina coast. (Named for William 

 Maclure, founder of the Academy of Natural Science? at Philadelphia.) 



Raia mnclnru, LE SUEUR, Jour. Ac. Nat. Sci. Phila., 1817, 41, Rhode Island; DUMKRIL, Elaemo- 



branches, i, 614, 1870. 

 Pteroplaiea maclura, GUNTHER, Cat., vni, 487,1870; JORDAN & GILBERT, Synopsis, 46,1883. 



129. PTEROPLATEA REBRIPUNCTATA, Peters. 



Breadth of disk twice the distance from tip of snout to vent. Snout 

 with a blunt projection ; anterior margin of pectorals undulate, convex 

 anteriorly and posteriorly, medially weakly concave; outer angle sharply 

 rounded ; posterior margins weakly convex, the posterior angle rounded, 

 covering outer half of base of ventrals ; spiracle without tentacle ; tail 

 with a low fold on its upper edge. Brown above, with thick-set black 

 points; a row of small close-set yellow spots on front of disk. Gulf of 

 California and southward, along the west coast of Mexico : common . (cre- 

 ler, abundant; pnnctatus, spotted.) 



Pteroplatea crebripunctala, PETERS, Monatsber. Berl. Akad., 703, 1869, Mazatlan. 

 130. PTEROPLATEA MARMORATA, Cooper. 



Disk about twice as broad as long, covered with perfectly smooth skin. 

 Tail 3f in length of disk, with a rather small cutaneous fold above and 

 below, the lower fold the longer, the upper about as deep. Interorbital 

 space a little shorter than the snout. Snout slightly prominent, but 

 forming a very obtuse angle. Olive brown, finely mottled everywhere 

 with darker, the dark forming reticulations around pale roundish spots ; 

 tail without dark rings. Caudal spine very small, present in all speci- 

 mens examined. Coast of California from Point Concepcion southward 

 to Cerros Island ; common, (marmoratus, marbled.) 



Pleroplatea marmorata, COOPER, Proc. Cal. Ac. Sci., in, 112, 1863, San Diego; JORDAN & GILBERT, 

 Synopsis, 47, 1883. 



Family XXVII. MYLIOBATID^E. 

 (THE EAGLE RAYS.) 



Disk broad; the pectoral fins not continued to the end of the snout, 

 but ceasing on the sides of the head and reappearing in front of the snout 

 as 1 or 2 fleshy protuberances (cephalic fins), which are supported 

 by fin rays. Tail very long and slender, whip-like, with a single dorsal 

 fin near its root, behind which is usually a strong retrorsely serrated 

 spine. Nasal valves forming a rectangular flap, with the posterior mar- 

 gin free, attached by a frenum to the upper jaw. Skull less depressed 

 than usual among rays, its surface raised so that the eyes and spiracles 

 are lateral in position. Teeth hexangular, large, flat, tessellated, the 

 middle ones usually broader than the others. Ovoviviparous. Skin 

 smooth; no differentiated spines on the pectorals in the males, the sexes 



