1863.] 



MR. W. K. PARKER ON PALAMEDEA. 



517 



(Nycticorax ardeola 4 

 Tigrisoma leucolophmn . . 4 

 Eurjpyga helias 3 

 Cancroma cochlearia .... 5 

 Balseniceps rex 5 



' Leptoptilus argala 4 



Scopus umbretta 4 



Threskiornis sethiopicus . . 5 



Platalea leucorodia 6 



'' Phoenicopterus antiquorum 5 



Palamedea chararia 4 



Plectropterus gambensis* . 7 



Anser palustris 9 



Cygnus olor 11 



Daflla caudacuta 7 



Anas boschas 8 



^ Mergus albellus 8 



Psophia crepitans 4 



Otis tarda 5 



( CEdicnemus crepitans .... 5 



Plovers, j Vanellus cristatus 4 



[ Charadrius hiaticula .... 3 



Ibidinae. ■ 



Anatinae. ■^ 



Gruinae. 

 Otinae. 



Long-billed 

 Plovers, 



Snipes. 

 Jacanas. 



Ostriches. 



G-uUb.- 



Petrels. - 



Grebes. 

 Totipalmatas. 



Divers. 



Penguins. 



■ Haematopus ostralegus .... 4 

 Himantopus melanopterus 4 



Numenius arquata 5 



Totanus fuscus 4 



Scolopax gallinago 4 



gallmula 3 



Parra jacana 4 



Dromaius ater 11 



Struthio camelus 9 



Apteryx australis 4 



Tinamus robustus 8 



Glareola torquata 4 



Gavia ridibunda 4 



Larus canus 4 



PufSnus brevicauda 5 



Diomedea exulans 5 



Podiceps rubricoUis 9 



Phalacrocorax carbo 9 



Colymbus septentrionaUs . 11 



Uria troile 5 



Alca torda 4 



Spheniscus demersus .... 4 



This table is large enough for all reasonable purposes ; and its re- 

 sults are very striking, and cannot have liad their extreme uniformity- 

 caused by chance. If we leave out all those birds which, for swim- 

 ming and especially diving purposes, have the sacrum extremely long 

 and much anchylosed, such as the Sifters, Grebes, Loons, Cor- 

 morants, and also the Ostriches (excluding the Apteryx), we shall 

 have four post-acetabular joints as the medium number. A large 

 proportion of all birds have exactly four vertebrae in rear of the 

 thigh-bones ; many have only three, and about as many more have 

 five. As a rule, the small birds of a group have the tendency to drop 

 a joint occasionally ; thus the little Estrelda has one less than the 

 other Finches, the Dotterel one less than the other Plovers, and the 

 Crake one less than the other Rails. The medium-sized rapacious 

 birds, both nocturnal and diurnal, have only three. Now, if we con- 

 sider that all the vertebrae above four in the posterior part of the 

 Duck's pelvis really belong to the tail, then, as I long ago found, the 

 ploughshare-bone is composed of ten segments, as four of the ap- 

 parently sacral bones are really caudal ; and as there are eight inter- 

 mediate vertebrce, the large number of twenty-two is obtained — one 

 more than the Archeopteryx possesses according to Professor Owen's 

 method of enumeration. 



Also in the Palamedea two of the anchylosed bones belong to the 

 tail ; there are six free bones, the last having had a rather late ad- 

 dition in the penultimate joint, so that it may be considered as 

 eleven : this gives us nineteen caudal vertebrse for the subject of this 

 paper — only two less than in the Archeopteryx. The same method 

 gives us twenty-four for the Swan, sixteen for the Emeu, and twenty- 

 two for the Cormorant. 



That five of the so-called sacral vertebrae of the Palamedea belong 

 to the dorso-lumbar region is evident, because the first three have 

 haemapophyses reaching the sternum, and on the right side there 



* Jnseranas melanopterus, a very Gruine Goose, has only 6. 



