that comiect the Orders and Families of Birds. 507 



other extreme groups, much of the habits of the land birds. A 

 portion of the group before us, the Petrels, seem even to employ 

 their feet in their own element as if on land, walking, as it were, 

 on the surface of the waters *. We have thus arrived at the 

 termination of the last family of the order, and have to look for 

 its connexion with the first. This link is immediately supplied 

 by the before-mentioned genus Pacht/ptila, in which the bill, 

 broad and depressed at the base, assumes the character of that 

 of the AnatidcB^. There is indeed a considerable approximation 

 and interchange of character between the two groups. The bill 

 of some species of Anser may be observed to become gradually 

 less broad and more compressed, so as to bring them closely to 

 the Petrels; while again the web that connects their toes is equally 

 curtailed in extent, until in one species, the Semipalniated Goose 

 of Dr. Latham, figured in the Supplement to his ''^Synopsis," we 

 may observe no greater web than may be seen among man)^ of 

 the Sterna. On the other hand, the same membrane is so ex- 

 tended in some of the Petrels X, as to equal the most dilated web 

 observable among the Anates. We may also add that the divi- 

 sions of the Procellaria, as they approach the Anatida, become 

 gradually more nocturnal in their habits, and thus adopt a charac- 

 ter common to a great portion of the latter family §. Here then 



in 



* " Celui (sc. le nom) de Pttrel, Petit Pierre, leur vient do I'habitude de marcher 

 sur I'eau en s'aidant de leurs ailes." Cuv. Regne Anim. i. p. 515. " Dans leur vol, 

 lis somblent effleurer les vagues de la mer, mais ils se posent tr^s rarenient sur la sur- 

 face de cet element, qu'ils semblent redouter, puisqu'on ne les voit jamais nager, bien 

 moins se submerger; ils semblent pi6tonner sur la surface des eaux, mais loujours te- 

 nant les ailes droites et en I'air." Temm. Man. p. 801. 



t " Les Prions {Pachyptila, 111.), qui, semblables d'ailleurs aux Petrels, auraient 

 les narines s6par6es comme les Puffins, le bee 61argi k sa base, et ses bords garnis ex 

 t^rieurement de lames comme les Canards." Cuv. Regne Anim. i. p. 517. 



;}: As in P.capensis, Linn. 



^ " Tout le genre (sc. Procellaria) est compost d'oiseaux plus ou moins demi- 

 VOL. XIV. 3 U nocturnes, 



