DIVING PETRELS. 91 



obliquely, so that the nostrils open upwards, a feature evidently produced by the div- 

 ing habit, in order to prevent water from being forced into the ' nose,' as this tube, 

 with great propriety, may be called. The total absence even of a rudiment of a hind 

 toe is notable, and so is the absence of an ambiens muscle, and of the accessory femora- 

 caudal, and accessory semitendinosus. It is, in short, a group quite generalized, as is 

 evident from many of its anatomical features, though highly specialized in all that is 

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

 ical distribution is tropical and antarctic. Rev. A. E. Eaton, from whom we have 

 quoted above in another connection, writes of Pelecanoides winatrix, the common 

 diving petrel, which he observed at Kerguelen Island, as follows : " This bird, as 

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

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

 out any interruption in the action of their wings, and also emerge from beneath the 

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

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

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

 in communities of considerable size, which are excessively noisy. Diving petrels, on 

 the other hand, are more domestic in their mode of living, fishing and flying for the 

 most part in pairs or alone, and building sporadically. They had begun to pair 

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

 Their burrows are about as small in diameter as the holes of bank martins ( Clivicola 

 riparia) or kingfishers (Alcedo ispida). They are made in dry banks and slopes, 

 where the ground is easily penetrable, and terminate in an enlarged chamber on whose 

 floor the egg is deposited. Some of the burrows are branched, but the branches are 

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

 Before the egg is laid, both of the parents may be found in the nest-chamber, and may 

 often be heard moaning in the daytime : but when the 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 noise. There seems to be a difference 

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

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

 made from E to C in the tenor." 



ORDER VII. ORALLY. 



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

 though formerly in a much worse condition, for the Grallae of olden times comprised, 

 besides those here admitted, the whole order Herodii, and the super-families, Anhim- 

 oideae and Phcenicoptroideae. It would, perhaps, be an improvement to remove the 

 first two super-families of the present order, viz., Chionoideae and Scolopacoideae, to 

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

 may expect to see the step taken some day. 



As it is, the members of the present order may, in general, be distinguished from 

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

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

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

 any and all of the Cecomorphse at first sight. They are all schizognathous, most of 



