16 A MANUAL OF THE BIRDS OF AUSTRALIA. 



forked, the legs short or comparatively long, the wings always long and pointed. 

 On account of internal differences two families have been separated, the long-legged 

 species having the expansor secundariorum, a wing muscle present, and also the 

 accessory semitendinosus, a leg muscle present, these muscles being absent in all 

 other Petrels, small or large. In addition, the former are said to possess no caeca, 

 while the latter generally have. Superficially the so-called long-legged forms have 

 the tarsal covering anteriorly scutellated or booted, all the remainder having a 

 completely reticulate tarsus. Osteologically there is very little distinction between 

 these as far as criticism has yet extended but it is quite possible that there may be 

 two families separable later, but at the same time many more will certainly be 

 demanded for other groups. Geographically the long-legged forms are southern, 

 the short-legged ones northern, the former penetrating into the Antarctic Circle to 

 breed, also ranging to north of the Equator rarely, the latter never breeding south 

 of the Equator but sometimes in the Arctic Circle. Consequently all the Australian 

 species are long legged, but even these present quite appreciable differences, most 

 of the species being regarded as generically separable. The ambiens muscle is 

 absent from Fregetta (sensu lato) while in Oarrodia it is present but the tendon does 

 not cross the knee. These two genera are not distantly related. Basipterygoid 

 processes are said to be entirely absent in Pelagodroma and Oceanites of the long- 

 legged group while they appear as minute prickles in the short-legged series. Again, 

 in the former group there are ten secondaries only. 



Genus OCEANITES. 



Oceanites Keyserling und Blasius, Wirbelth. Europa's, p. xciii., (before April) 1840. (Type 

 by monotypy) : Thalassidroma wilsoni Bonaparte = ProceUaria oceanica Kuhl. 



Small Storm-Petrels with small hooked bills, long wings, medium emarginate 

 tail and long legs and feet. The bill has the tubular nostrils semi -erect, about half 

 the length of the bill, the tip strongly hooked but weak, the latericorns a little bowed 

 and basally widening. The under mandible has the rami a little bowed and divergent 

 similar, the tip also weak. The wing is very long, the first four primaries forming 

 the tip, the second being longest, the third longer than the first which is longer than 

 the fourth ; the secondaries are very short. The tail is slightly emarginate, a little 

 less than half the length of the wing, the feathers broad. The legs are long, the tibia 

 exposed for about one-third the length of the metatarsus, which is about hah* the 

 length of the tail with the tarsal covering complete in front, but obscurely scutes 

 may be seen indicated, while the back is reticulated. The toes are long, the inner 

 shorter than the middle and outer which with their claws are subequal, the claws 

 elongate, that of the middle toe longest. The anterior toes are fully webbed between, 

 the hind-toe reduced to a minute, almost negligible, speck. 



Coloration uniform, save white upper and under tail -coverts. 



9. Oceanites oceanicus. YELLOW-WEBBED STORM-PETREL. 



[Procellaria oceanica Kuhl, Beitr. Vergl. Anat., p. 136, 1820 (pref. April 9th) : South Atlantic 



Ocean. Extra-limital.] 



Gould, Vol. VII., pi. 65 (pt. xxn.), March 1st, 1846. Mathews, Vol. II., pt. 1, pi. 68, May 



30th, 1912. 



Oceanites oceanicus exasperatus Mathows, Birds Austr., Vol. II., pt. 1, p. 11, pi. 68, May 30th, 



1912 : New Zealand Seas. 



DISTRIBUTION. Southern Australian Seas as far north as South Queensland. ? Breeding 

 at Cape Adare, Antarctic Circle. 



Adult male. Sooty-black above and below, paler on the greater wing-coverts, 

 which are fringed with whitish ; upper tail-coverts pure white like the feathers on 



