370 



THE PLAGIOSTOMIA. 



SyM PTERYGIA ACUTA. 

 Plate 27, fig. 1-2; Plate 57, fig. 1 (heart); Plate 68, fig. 3^ (skeleton). 



Sympterygia acuta Garman, 1877, Proc. Bost. soc. nat. hist., 19, p. 206. 



Sympterygia bonaparlii Berg, 1895, An. Mus. nac. Argent., ser. 2, 4, p. 15; Evermann & Kendall, 

 1906, Proc. U. S. nat. mus., 31, p. 72. 



Disk rhomboid, length to end of pectorals about equal width, acute in front, 

 rounded on lateral and hinder angles and margins. Pectorals extended far in 

 front of the cranium, narrowly separated by the end of the snout, anterior mar- 

 gins slightly concave opposite the spiracles. Eyes small, spiracles little larger, 

 distance apart two thirds of their distance from the margins of the disk. Mouth 

 small, curved forward in the middle. Nostrils and narial valves as in Raia. 

 Teeth small in 40^5 rows, sharp in the middle of the mouth. Ventrals broad, 

 with a rather shallow notch on the outer margin. Vent in middle of the total 

 length. Tail depressed, with lateral folds, with two dorsal fins separated by an 

 interspace and tubercles, and with a rudimentary caudal fin. Back, tail, and 

 forward half of each pectoral rough with small spines; a row of broad-based 

 hooked tubercles from head to dorsal fin. Total length 13.5, disk including 

 ventral fins 9, snout to pores 8.5, and tail 5 inches. 



Reddish brown, darker on the middle of the back and on the tail; white 

 beneath. 



Buenos Aires, secured by the Hassler Expedition. 



PSAMMOBATIS. 

 Psammohatis GtJNTH., 1870, Cat. fishes Brit, mus., 8, p. 470. 



Disk rounded, snout short, pectorals extending in front of skull, narrowly 

 separated by the snout. Mouth transverse; teeth small. Spiracles small, 

 close to the eyes. Ventrals deeply notched. Tail depressed, with lateral folds, 

 two dorsals, and a rudimentary caudal. Back roughened with small spines 

 and tubercles. 



Southern South America. 



PsAMMOBATIS SCOBINA. 



Raia scobina Philippi, 1857, Wiegm. arch., p. 270; 1892, An. Mus. nac. Zool., 1, Chile, p. 2 extra, pi 



1, f. 1; LoNNBERG, 1907, Hamb. magal. sammelreise, Fische, p. 7. 

 Uraptera scobina Dum6ril, 1865, Elasm., p. 574. 

 Psammobatis rudis GtJNTH., 1870, Cat. fishes Brit, mus., 8, p. 470; 1880, Challenger rept. Zool., 1, p. 20, 



pi. 10; LoNNBERG, 1907, Hamb. magal. sammelreise, Fische, p. 7. 

 Psammobatis rulrum Jordan, 1891, Proc. U. S. nat. mus., 13, p. 334. 

 Psammobatis scobina Evermann & Kendall, 1906, Proc. U. S. nat. mus., 31, p. 71. 



