that connect 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 Pachyptila, in which the bill, 
broad and depressed at the base, assumes the character of that 
of the Anatidæ*. There is indeed à 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 theirtoes is equally 
curtailed in extent, until in one species, the Semipalmated Goose 
of Dr. Latham, figured in the Supplement to his ** Synopsis," we 
may observe no greater web than may be seen among many of 
the Sterne. On the other hand, the same membrane is so ex- 
tended in some of the Petrels b as to equal the most dilated web 
observable among the Anates. We may also add that the divi- 
sions of the Procellariæ, as they approach the Anatide, become 
gradually more nocturnal in their habits, and thus adopt a charac- - 
ter common to a great portion of the latter family&. Here then 
Sh | in 
* « Celui (sc. le nom) de Pétrel, Petit Pierre, leur vient de l'habitude de marcher 
sur l'eau en s'aidant de leurs ailes." Cuv. Regne Anim. i. p. 515. ** Dans leur vol, 
ils semblent effleurer les vagues de la mer, mais ils se posent trés rarement sur la sur- 
face de cet élément, qu'ils semblent redouter, puisqu'on ne les voit jamais nager, bien 
moins se submerger; ils semblent piétonner sur la surface des eaux, mais s toujours te- 
nant les ailes droites et en l'air." Temm. Man. p. 801. 
+ * Les Prions (Pachyptila, Ill), qui, semblables d’ailleurs aux Pétrels, auraient 
les narines séparées comme les Puffins, le bec élargi à sa base, et ses bords garnis ex 
térieurement de lames commé les Canards." Cuv. Regne Anim. i. p. 517. 
t Asin P. capensis, Linn. 
ed Tout le genre (sc. Procellaria) est composé d'oiseaux plus ou moins demi- 
VOL. XIV. 3U nocturnes, 
