Description of the skeleton of Inia geoffrensis and of the skull of Pontoporia blainvillii, with remarks on the systematic position of these animals in the order Cetacea / by William Henry Flower.

Flower, William Henry, 1831-1899.

Date:: 1866

Credit: Description of the skeleton of Inia geoffrensis and of the skull of Pontoporia blainvillii, with remarks on the systematic position of these animals in the order Cetacea / by William Henry Flower. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

1/40 (page 87)

$IV. Description of the Skeleton of Inia geoffrensis and of the Skull of Pontoporia blainvillii, with Bemarks on the Systematic Position of these Animals in the Order Cetacea. By William Henry Flower, F.B.S., F.B.C.S., F.Z.S., Ac., Conservator of the Museum of the Boyal College of Surgeons of England. Read November 22nd, 1866. [Plates XXV. to XXVIII.] I. On the Skeleton of Inia geoffrensis. Of the several species of Cetaceans which are inhabitants of the waters of the Amazon and its great tributary streams, one has particularly attracted the attention of zoologists on account of certain peculiarities of its external conformation and of its skull and teeth, the only parts of its structure hitherto described. The Inia, so called by M. Alcide d Orbigny, from the name by which the animal is known to one of the Indian tribes of Bolivia, is chiefly characterized by the long, narrow, and almost cylindrical rostrum, furnished with scattered, stout and crisp hairs, by the broad, long, and obtuse pectoral fins, by the dorsal fin reduced to a mere ridge, and especially by the development of a large lobe on the inner side of all the posterior teeth. The species is mentioned by Spix and Martius * as Del'phinus amazonicus; but for the most complete account of its external characters, habits, and geographical distribu- tion we are indebted to d’Orbigny, who described it under the name of Inia holiviensis^. He also gives a figure of the animal, and a side view of a skull which he brought home and deposited in the Museum at the Jardin des Plantes, with some details of the teeth. I will quote from this memoir two observations—the first referring to the habits, the second to the stiuctuie of this singular Cetacean:—“ Toutes ces observations nous font regarder cette espece comme ayant des mceurs beaucoup plus terrestres qu’aucune des especes connues.”—“ Tous ces caracteres reunis a une dorsale peu apparente, nous font proposer la formation d’un nouveau genre, qui etablerait le passage entre les sousous [Platanista] et les stelleres ” [Sirenia~\. * Reise in Brasil, t. iii. pp. 1119 & 1133 (1831). Yon Martius states that his Delphinus amazonicus agrees very closely with Desmarest’s description of D. geoffroyi, and even suggests that it may possibly belong to the same species.. His description of the teeth is sufficient to determine the animal spoken of; but he says “ pinna dorsalis distincta, elata.” Perhaps he has here confounded it with some of the other species of fresh- water dolphins of the Amazon, the existence of which he did not suspect. The rude little figure he gives (fig. 34) more resembles Delphinus fluviatilis (Gervais) of Castelnau’s Yoyage than the Inia. t Nouv. Ann. Mus. Paris,'tom. iii. p. 23 (1834). VOL. VI.—PART III. O$