636 SIR SIDNEY HARMBR ON COMMBRSON's DOLPHIN 



as belonging to a single species. I have to thank Prof. R. 

 Anthony for the information that the skull figured in the 

 ' Osteographie ' (figs. 1, la) is from the Cape of Good Hope, 

 Dussumier, 1827, although he thinks that the lower jaw figured 

 (1 h) may not be from the same specimen. It may no doubt 

 be assumed that Dussumier's specimen at least belonged to 

 C. heavisidei. 



The following may be noted as points of agreement between 

 the type-skull of C. heavisidei and Schlegel's figures : — The small 

 lateral lobes at the base of the rostrum on each side ; the narrow 

 posterior expansions of the maxillae, not completely covering the 

 orbit ; the shape of the nasals, which do not quite touch one 

 another and leave a triangular part of the frontals exposed between 

 themselves and the mesethmoid ; and the broad posterior ends of 

 the premaxillse, both of which nearly reach the nasals. In. 

 Van Beneden and Gervais' figure most of these resemblances are 

 also noticeable, and attention may be specially directed to the 

 right j^remaxilla, which reaches the nasal behind. 



Cephalorhynchus Gray, 1850 (see Flower, P.Z. S. 1883, p. 473, 

 and True, 1889, Bull. U.S. Nat. Mus. no. 36, pp. 108, 176). 



0. COMMERSONII Lacep. 



Delphinus commersonii, " Le Jacobite," Lacepede, 1804, Hist. 

 Nat. Get, pp. xliv, 317 (referred to by Quoy and Gaimard, 1824, 

 Toy. ' Uranie,' p. 87 ; and by Lesson, 1827, Yoy. ' Coquille,' 

 p. 181). 



Delphinus commersonii Desmarest, 1822, Mamm. 2^ Partie, 

 p. 517. 



Phoccena commersonii Lesson, 1827, Man. Mamm. p. 414. 



Lagenorhynchus floweri Moreno, 1892, Rev. Mus. La Plata, 

 iii. p. 385, pis. viii., ix. 



Lagenorhynchus cruciger'^. Bruce, 1915 {nee auctt.), "Piebald 

 Porpoise," Scotia Rep. vol. iv. p. 500, pi. i. 



Known localities. — Tierra del Fuego, Straits of Magellan, coast 

 of Patagonia, Falkland Islands. 



External characters. ■ — Length at least 140 cm. Head conical, 

 without distinct beak. Dorsal fin bluntly triangular, not falcate. 

 Flippers rounded at the end, not falcate. Most of the sides and 

 ventral surface silvery white, this colour extending completely 

 across the back, between the head and the dorsal fin. A large 

 white, median, pear-shaped area, widest behind, on the throat. 

 Head, tail, caudal, pectoral, and dorsal fins jet-black (the fins on 

 both surfaces), a narrow dorsal band of black passing obliquely 

 from the tail to just beyond the dorsal fin, a broad black band 

 extending across the ventral side between the flippers, produced 

 backwards into a median, acuminate process. A black area 

 surrounding the reproductive opening. White and black areas 

 very sharply defined. Visible teeth 29-30 on each side of 

 each jaw. 



