ON MYLIOBATIS AND PTEROCEPHALA. 12'] 



Lowe's "Fishes of Madeira," and as it differs in some particulars 

 from my specimen I think it best to give a detailed description of 

 the latter, with accurate measurements of it. 



Body, smooth — dark olive-brown above, white beneath. 



Head somewhat rounded, with curved convex snout and rising 

 abruptly from thence to a prominent vertex or forehead extended 

 across between the eyes. 



Eyes at side of head, large and somewhat overhung by the pro- 

 jecting edge of head. Immediately behind each eye is a large open 

 spiracle. 



The greatest width of the body and pectoral fins 32^ inches, at a 

 short distance behind the head. The back at this part is somewhat 

 raised and slopes towards the snout and the tail. 



Pectoral Fins widely spread, broad and slightly falciform, the 

 concavity being directed backwards towards the tail. 



Tail, 24 inches long, at first thick, tapering gradually to a whip- 

 like termination, with a dorsal fin situated 4^ inches from the root 

 of the tail, and armed with two bony spines placed just behind the 

 dorsal fin 3 one of these is 35 inches and the other 2 inches long j 

 both are finely serrated on each side — the serrations directed 

 backwards. 



Ventral Fins, broad, 11^ inches across from point to point. Mouth 

 beneath the head, transverse and protected by a large flat lip. 

 Teeth flattened with hexagonal outline and fitted together like a 

 mosaic pavement. 



Both in the upper and under jaw there is a central row of 

 transversely extended denticles with smaller and narrower ones 

 quincuncially arranged at either side. 



The upper set of denticles form an arc of a circle to work against 

 the hollowed under set ; width of central denticles above, ij inch. 



The mouth contained some broken remains of the shell of a 

 mollusk. 



Total length of body from middle of snout to tip of tail, 

 44 inches. 



