70 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxi. 



fins and on base of tail; an interrupted series of spines along median 

 dorsal aspect of tail; 1 spine between dorsals; below smooth, except- 

 ing a moderatel}' broad patch of fine prickles on antero-lateral border 

 in reg-ioii anterior to nostrils and on each side of snout; snout smooth. 

 Color in alcohol, above light brown with large faint dark-brown 

 spots, giving it a coarsely mottled appearance; a large ocellus at 

 middle base of each pectoral, the center dark brown, surrounded b}" 

 gra>^; traces of dark brown cross-bars on tail; each side of snout 

 with pale area, probably hyaline in life; below entirely white, except- 

 ing a long triangular dark-brown spot on the snout, its apex toward 

 mouth; sj^mmetrically arranged bluish pores, thick anteriorly, becom- 

 ing fewer and disappearing on abdomen. 



5. RAJA MICROPS Giinther. 



Raja microps Gunther, Cliallenger Kept., ZooL, I, 1880, p. 11, pi. iv, mouth of 

 Rio (le la Plata. — Beiuj, Anal. Mus. Nac. Bueno.s Aire.s, IV (2d ser., I), 

 1895, p. 14 (Mar del Plata; Rio de la Plata). 



Concerning this species. Berg saj^s that it occurs with less frequency 

 than the former species [li. agasslzl and R. platana] from which it is 

 distinguished principally by the much shorter snout; and usuall}" there 

 are 34 series of pavement teeth. 



The only example in our collection is a female from Buenos Aires 

 market. We have identified it with this species, although it does not 

 agree in ever}" wa}- with Giinther's description and figure. There is 

 no trace of the conspicuous fan-shaped patches of muciferous tubes 

 just posterior to the head, mentioned and figured by Gunther. 



The following notes are taken from our specimen: Total length 

 20.87 inches; length of disk about 2.31 in total length; width of disk 

 about 1.51; snout about 3.34 in length of disk; interorbital space about 

 3.11 in snout. Teeth flat, -l^ series in upper jaw and 3<» in the lower; 

 snout short, its angle greater than a right one; anterior margin of 

 pectoral slightly sinuous from snout to the rounded outer margin. 



Ventrals deeply emarginate, with crenate edges; tail flat, with a 

 narrow fold on each side; series of spines along the hack and tail to 

 the first dorsal, and one spine between the fins; a spine behind each eye 

 and opposite the spiracles; a spine in front of the upper margin of 

 each eye and one on each side of the body opposite the spiracle and in 

 line with the anterior margin of pectoral fin; a broad patch of prickles 

 along anterior margin of pectoral, diminishing in width to the snout; 

 space betAveen the eyes prickly; a line of prickles along each side of 

 median line of spines of the back, also along each side of base of tail 

 for a short distance beyond base of ventrals; a narrow strip of prickles 

 on each side of lower part of snout. Color olivaceous gray, with faint 

 traces of darker spots. 



