DIVING PETRELS. 91 



obliiiiifly, so thai the nostrils open uinvaiils, :i feature evidently in-oiluceil by the (liv- 

 ing habit, in ortler to prevent water from being foreed into the ' nose,' as liiis tube, 

 witli great pro]iriety, may be called. The total absence even of a rudiiMent of a hind 

 toe is notable, and so is the absence of an ambieii.i muscle, and of the ucccssonj femora- 

 caudal, and accessor)/ semilendinosus. It is, in short, a group quite generaliy.ed, as is 

 evident from many of its anatoniical features, though highly s]>eciali/.ed in all that is 

 affected by its diving habits. The group is very restricted in forms, and its geograph- 

 ical distril)ution is tropical ami antarctic. Kev. A. E. Eaton, from whom wc have 

 quoted above in anotlier connection, writes of I'elccaiioides iiriiiiitri.i; the common 

 diving ])etrel, which he observed at Kerguelen Island, as foUow.s : " Tins bird, as 

 Professor Wyville Thomson ■well observes, has a close general likeness to Allc alle. 

 IJotii of thcni have a hurried flight ; both of them, while flying, dive into the sea with- 

 out any interru]>tion in the action of their wings, and also emerge from beneath the 

 surface flying, and they botli of them swim with the tail rather deep in the water. 

 But this resenibl.anee does not extend to other particulars of their habits. The rotche, 

 when breeding, usually flies and fishes in sm.all flocks of six or a dozen birds, and builds 

 in communities of consideraV)le size, which are excessively noisy. Diving jictrels, on 

 the other liand, are more domestic in their mode of living, fishing ami flying for the 

 most jiart in ])airs or alone, and building sporadically. — They liad begini to pair 

 when wc reached Kerguelen Island. The first egg was found on the 31st of October. 

 Their burmws are about as small in diameter as the holes of liank martins (Clivicola 

 ripariit) or kingtishcrs (Alcedo I'gpidt). They .arc made in dry banks and slopes, 

 where the ground is easily ]ienetrable, and terminate in an cnlargeil chamber on whose 

 floor the egg is deposited. Some of the- burrows are branclu'd, l)ut the branches are 

 without terminal enlargements, and do not appear to be put to any use by the birds. 

 15ef(n-c the egg is laid, both of the ])arents may be found in the nest-clianiber, and may 

 often be lu'ard moaning in the daytime: but when tlie females begin to sit, their call 

 is seldom heard, excepting at night, when the male in his flight to and from the hole, 

 and his mate on her nest, make a considerable noi.se. There seems to be a difference 

 of a semi-tone between the moans of the two sexes. The call resembles the syllabic 

 'oo' pronounced with the mouth closed, while a slurred chromatic ascent is being 

 made from E to C in the tenor." 



Order VII. — GRALL.E. 



The order Grallae, as here defined, is still a rather heterogeneous assemblage, 

 though formerly in a much worse condition, for the Gralhv of olden times com])riseil, 

 besides those here admitted, the whole order Hcrodii, and the sui>er-families, Aidiim- 

 oideai and Pluenicoptroidea;. It would, perhaps, be an improvement to remove the 

 first two supei-families of the ])resent order, viz., Chionoidcai and Scolopacoidea?, to 

 the foregoing order, retaining the name Gralla; for the remaining forms only, and we 

 may expect to see the ste]) taken some day. 



As it is, the members of the ]>resent order may, in general, be distinguishetl from 

 those of the foregoing one by the absence of full webs between tlie anterior toes. 

 True, we have a few ' waders,' with entirely palmate feet, viz., the avocets, but the 

 enonuous length of their legs, and the long and thin bill, make them separable from 

 aiTj- and all of the Cecomori)ha? at first sight. They are all schizognatlious, most of 



