Dr. H. Burmeister on some Cetaceans. 101 



On Delphinus microps. 



Of this species we have now three skulls in the museum, it 

 being the commonest species on the coast of Brazil south of the 

 equator. I saw many troops of them during my voyage in the 

 sailing vessel which first brought me here. 



The a,nimal is of the size and colour of your Delphinus Walkeri 

 (fig. 100), and I think it may be the same species, if the skull is 

 not very different. My three skulls are of equal size, 17 Rhenish 

 ( = 18'] 5 English) inches in length, and 7 {-=7^ English) inches 

 in breadth at the widest point on the temporal arch, beneath the 

 fossa temporalis. They have from forty-seven to forty-nine teeth 

 in the upper jaw, and from forty-four to forty-eight in the lower; 

 but the number seems to be variable, as the first and last teeth 

 are very small, and often wanting on one side when present on 

 the other. The upper jaw always has some more teeth behind, 

 and the lower jaw probably some more in front. The form is 

 exactly like your figure (pi. 25), even the deep groove on the 

 right side of the frontal tubercle being the same, and the occi- 

 pital crest very prominent in front, perhaps more so than in 

 your figure. The teeth are six to an inch in the middle of the 

 jaw. 



In its general form the skull is nearly allied to that of Steno 

 attenuatus, which I received last year from a friend on his return 

 from Europe in a sailing vessel. This vessel took the animal in 

 the middle of the Atlantic, south of the line ; and my friend 

 preserved the skull for me, the animal having been eaten by the 

 sailors. The skull is exactly 17 inches long, and agrees pre- 

 cisely with your figure in the ' Vovage of the Erebus and Terror/ 

 pL 28. 



Lastly, I have also received the skull of Delphinus Styx (Voy. 

 Ereb. and Terr. pi. 21) from a sailor, who captured the animal 

 near Madeira. I am also in expectation of an entire well-pre- 

 served skeleton of a Dolphin taken in the river two miles above 

 Buenos Ay res ; bnt the owner would not give me the bones till 

 to-day. 



Orca magellanica, n. sp. PI. IX. fig. 5. 



This animal is known only by a skull found on the shore of 

 the province of Buenos Ayres, in lat. 38° 50' S., near the mouth 

 of the small Rio del Cristiauo muerto. It seems to be very like 

 Orca capensis, but rather more slender, as is proved by the fol- 

 lowing measurements of the skull, compared with the sam^ in 

 Orca gladiator and capensis, as given by Dr. Gray in his ' Cata- 

 logue of Seals and Whales, ed, 2. pp. 280 & 284. 



