440 



THE PLAGIOSTOMIA. 



Width of disk 1,430, length from snout to ends of ventrals 1,130, and length 

 of tail from the dorsal 640 mm. 



Greenish grey with white spots of different sizes irregularly distributed; 

 below dirty white darker on the pectorals. 



Admiralty Islands. 



Aetobatus. 



Aetobatus Blainv., 1816, Bull. Soc. philom., p. 112. 

 Sloasodon T. Cantor, 1849, Malay, fishes, p. 434. 



Pectorals slightly falciform, not continuous forward to the snout. Rostral 

 fins separated from the pectorals and at a lower level on the sides of the head. 

 Teeth in a single row on each jaw, fused, lower pavement produced. Head 

 prominent, narrowing downward and forward on the sides; snout narrower, 

 produced. Anterior nasal valves confluent; a median notch in the preoral flap. 

 Ventrals narrow, elongate. Tail long, slender, bearing a dorsal fin and a ser- 

 rated spine above the basal portion. As in some other genera several species so- 

 called are described to complete the record, at the risk of ranking them too high. 

 A larger series of specimens will no doubt reduce the number of species to one 

 with one or more varieties. 



Fossil species of this genus have been discovered by Agassiz and others 

 in the Eocene and later formations. Mesobatis Leidy from the phosphate beds 

 of South Carolina is intermediate between Aetobatus and Pteromylaeus; it has 

 small teeth between the ends of the broad ones. 



Snout long tapering, acute 



uniform, or spotted with whitish 



Snout long, broadly rounded at the end 



spotted with white .... 



Snout short, tapering, blunt 



spotted thickly with small dark-edged spots 



flagellum (page 440) 

 narinari (page 441) 

 ocellatus (page 442) 



Aetobatus flagellum. 



Raia flagellum Schneider, 1801, Bloch Ichth., p. 361, pi. 73. 



Raia guttata Shaw, 1804, Zool., 5, p. 285, pi. 142. 



Aetobatus flagellum Mullbr & Henle, 1841, Plagios., p. 180; Blyth, 1860, Journ. Asiat. soc. Bengal, 



29, p. 37; DuMERiL, 1861, Arch, mus., 10, p. 242, pi. 20, f. 3; 1865, Elasm., p. 642; Klunzinger, 



1871, Syn. fische, 2, p. 246; Annandale, 1909, Mem. Ind. mus., 2, p. 57. 

 Goniobatis flagellum Agass., 1858, Proc. Bost. nat. hist., 6, p. 385. 



This species difTers from other species of the genus in length and sharpness 

 of snout, and in colors. The snout is longer than broad and tapers to a sharp 



