•of a new Gemis cf Fish numrd Polijptcra. 37 



than a twelfth part of its wliolc length : hut there is nothing 

 real in this ineaiiveiiienev. Tl>e iins of this iish, whieli 

 correspond to the extreniities of the mammalia, are tornicd 

 in sueh a mann<?r that it ean employ them at pleasure, like 

 the phoca>, cither for natation, or walking, or for re])tation. 

 We are already ;icquainted with a simiJar organization, that 

 of the Lophia, the peetoral and ventral fins of whieh are 

 plaeed at the end of carncous prolongations ; hut this gcK'US 

 belongs to the order of jugular Jishes, where the extre- 

 mities arc; found in a,n inverted order, and eannot serve for 

 &ttaehing these aninrals to any body but under eertain eir- 

 cumstances. 



'i'he bich'ir then in this respcet exhibits a more complete 

 analooy to quadrupeds. To appreciate its just value we 

 shall here give a description of the pectoral and ventral fins. 



'J'he anterior t^'xtremitv, whieh is 2 inches 7 lines, is 

 longer than the posterioii-, and t'lie arm is very little shorter 

 than the fin, being J inch 10 lines : it is very fiat, naked 

 internally, and covered with scales only on tlic exterior 

 side : it contains all the bones which compose the anterior 

 cxtrcnntv of quadrupeds. 



The omoplata is a large square piece at the top of whieh 

 is an apophysis, broad at the base, which articulates with 

 the back part of the plates of the head : the sternum is of 

 an elongated form, disposed transversely, and remarkable 

 for a large groove situated before : below is the clavicular 

 bone which projects outwards in such a manner as to ac- 

 company the humerus, and to serve like it for the articu- 

 lation of the fore arm. In regard to the humerus, it is a 

 very short small bone, of less breadth than the clavicle, 

 with \\hich it is accompanied : all these small bones are 

 separated only in young individuals : in adults they are 

 united in such a manner as to form one bone, where the 

 traces of their fornier separation are alwa\s indicated by 

 ♦juturce^ 



The fore arm is composed of two long, slender, and un- 

 fqual bones, the cubitus and the radius, which separate at an 

 angle of 50'^. A very thin round osseous plalc, w hich I 

 consider as a real carpus, occupies the centre of tiiis separa- 

 tion, 3Xu\ on the semicircular base of this triangle the apo- 

 physes which defend the radii rest : this kind of metacarpus 

 is terminated by fins. 



Among the nuisclcs with which the lore arm is provided, 

 wc distinguish an adductcjr, and particularlv large flexors 

 and extensors, which line the interior and exterior part of 

 the metacarpus. 



C 3 Tic 



