46 



original drawing from which Duharael copied the front 

 luilf of tlii.s aniniah It shows the appearance of a keel in 

 the middle of the back, which replaces the dorsal fin. Tab. 

 5, is a copy of a tracing of this drawing, kindly sent me by 

 M. De Blainville. It can scarcely be a Beluga. 



The external figure of this animal greatly resembles 

 the Hyperoodon, and it agrees in the hinder position of 

 the blower ; but the large size of the pectoral, and the 

 absence of the dorsal, prevent it being regarded as a spe- 

 cies of that genus. 



PoNTOPORiA, Graij. 



Skull roundish. Beak very long, compressed, with a 

 strong groove on each side above. Eyebrow with a long, 

 cylindrical crest. Lower jaw compressed, with a deep 

 groove on each side. Symphysis very long. Teeth small, 

 subcylindrical, smooth, rather hooked, acute. 



The PoNTOPORiA. Pontoporia Blainvillii. 

 Tab. 29. Skull. 

 Delphinus Blainvillii, Fremenville, Mus. Paris. 



White, with a black dorsal streak ; skull, with the 

 tubercles behind the blowholes, broad, slightly convex ; 

 eye-brows with a strong, longitudinal crest ; upper and 

 lower jaw with a deep, well-defined ridge on each side ; 

 teeth 44' small, conical, hooked, smooth ; symphysis more 

 than J the length of the lower jaw. 



Inhab. Monte Video. Skull, Mus. Paris. 



480 inches and lines. 

 V2-6 



8-0 



.5-9 ~ 



5-4 



Length of animal 

 „ skull 

 „ beak 

 „ symphysis 

 „ teeth line 



According to Desmarest, Fremenville saw a dolphin on 

 the coast of Brazil, which was 15 feet long, with a very 

 convex forehead ; ashy, with a white streak on each side 

 of the head, on the back, throat and belly. 



The Delphinus macrogenius, Fischer, Cuvier, 0.s.i. Fos.s. 

 v. 312, t. 23, /. 4, 5, /. 9—11, appears to belong to this 

 tribe. 



APPENDIX. 



During the time the Plates have been engraving, and the 

 text printing, the following new materials have come into 

 my hands, which I think may be a useful addition to the 

 knowledge of these difBcult animals. 



Bal^enid.e. 



From the examination I have been able to make of 

 the baleen of BaUeiioptera ro.strata, and of different 

 masses of small blades of Bahcna australis, it would ap- 

 pear as if there was, at least, in those two species, two 

 series of Baleen on each side of the palate ; the external 

 series being formed of large triangular blades placed at a 

 certain distant apart, and the internal, in BaUcnoptern 

 rostrata, foi'med of smaller, much thinner, triangular pieces, 

 placed much closer together and forming a very dense 

 screening apparatus; and in Balmna (uisiralis, the inner 

 series is formed of numerous separate narrow strips of 

 Whalebone, each ending in a pencil of hairs, which vary 

 in size from that of small twine to that of tape, half an 

 inch wide ; these are placed behind the others, and gradu- 

 ally increase in size from the innermost, to the broad ex- 

 ternal series. 



The Baleen or Whalebone, has generally been con- 

 sidered as the teeth of the whale ; but this must be a 

 mistake, for Professor Eschricht lias shown that the foetus 

 of Mef/aptera Boops [Danish Trans. 1845, xi. t. 4), has 



numerous teeth on the edge of the jaw, though they are 

 never developed. I am inclined to regard the Baleen as a 

 peculiar development of hair in the palates of these ani- 

 mals, and somewhat analogous to the hair found in the 

 palates of the genus Lepus. 



The Baleen or AVhalebone, affords good characters for the 

 separation of this family into sections. 



The Whalebone of the smooth-bodied whales without 

 any back fins, is elongate, much longer than broad at the 

 base, and gradually attenuated, and edged with a iringe of 

 equal, lengthened, fine, soft bristles. The Baleen is inter- 

 nally formed of a thin layer of fibres covered on each side 

 with a thick coat of ' enamel,' when dr}- and out of tlie 

 whale they are flat. The Whalebone of the plaited bellied 

 whale with a hunch (Megaptera) or a dorsal fin (Bala^nop- 

 tera), is short, broad, triangular, not much longer than broad 

 at the base, and rapidly attenuated, and is edged with a 

 series (sometimes, rather crowded) of elongate rigid unequal 

 bristles like fibres, which become much thicker and more 

 rigid near and at the tip, the Baleen is internally formed of 

 one or two layers of thick fibres, covered on each side with 

 a thin layer of enamel, and when dry and out of the palate 

 they are curled up and somewhat spirally twisted. 



The Baleen of the Bahenw is alone called Whalebone (or 

 rather If'halc-Jin, as it is usually called) in counncrce. The 

 Baleen of the other genera of this family is called Finner-Jin 



