12 BULLETIN 95, UNITED STATES NATIONAL MUSEUM. 



mtn. 



Tip of snout to origin of first dorsal 370 



Origin of first dorsal to origin of second dorsal 61 



Origin of second dorsal to tip upper caudal lobe 125 



Snout 35 



Distance between eyes 54 



Space between spiracles 49 



Tip of snout to anus 265 



Total length, outer border of pectoral 175 



Distance between angles of mouth 82 



Width of free portion of caudal 90 



Base of first dorsal 26 



Height of first dorsal 53 



Base of second dorsal 23 



Height of second dorsal 46 



Diameter of eye 10 



Body compressed ; snout rounded ; eyes small, inserted near margin 

 of disk; pectorals broad, distal margin truncate; ventrals narrower, 

 truncate; dorsals small, narrow at base, rather high, of about equal 

 size; caudal triangular, the lower lobe the longer; skin rough; en- 

 larged prickles along the median line of the back; small patches in 

 front of and behind the eyes, and two small patches on tip of snout on 

 either side of median line of head ; a single enlarged prickle, at a dis- 

 tance equal to diameter of eye from spiracle toward median line of 

 head. 



Color in alcohol, ashy gray, finely mottled and blotched with olive; 

 dusky areas on dorsal and caudal, larger and irregular in form ; ven- 

 tral surface white. 



Genus RHINOBATUS Bloch and Schneider. 

 10. RHINOBATUS PLANICEPS Garman. 



GUIATAEEA. 



Plate 2, fig. 3. 



RhinoMtus planiceps Gabman, Bull. Mus. Comp. Zool., 1880, p. 168; 

 Peru; Galapagos; Proc. U. S. Nat. Mus., vol. 3, 1880, p. 520; Paita, 

 Callao, and Galapagos Islands. — Joedan and Evkbmann, Fishes North 

 and Mid. Amer., vol. 1, 1896, p. 64. 



One specimen, field No. 09508, 76.3 cm. long, and five specimens, 

 field No. 09535, 19 to 21 cm. long, from Lobos de Tierra. 

 Dimensions of largest individual : 



mm. 



Total length 763 



Width of disk 267 



Distance from tip of snout to end of ventrals 408 



Distance from tip of snout to end of vent 315 



Distance from tip of snout to end of mouth 120 



Distance from tip of snout to end of nostrils 98 



Distance fx'om tip of snout to end of eye 100 



