302 PEOFBSSOE W. K. PABKEE ON THE 



liinder median piece, as in Podargus and Caprimulgus : when truly azygous it is called 

 here the medio-palatine. 



Now this difference does not depend upon the narrowness or breadth of the face. 

 The frog-like face of Podargus yields the most perfect typical instance of the Carinate 

 type of palate, whilst the delicate attenuated skull of the Sun-Bittern {Eurypyga helias) 

 lias its parasphenoid exposed along almost the whole extent of the palate. 



To one who is familiar with the structure of the skull and its development in the 

 Xowex types — Fishes, Amphibia, Reptiles — this is full of meaning. The skull of the 

 Ratitse is rich in even Batrachian characters ; and the one under consideration, that of 

 Thinocorus, is being read off by me, whilst writing, in the light of that of Testudo 

 grceca. 



I look upon Professor Huxley's Geranomorphae (Cranes and Rails, P. Z. S. 1867, 

 p. 457) as a great side branch of the Pluvialine stock, and not arising at any great 

 height above the Tinamidse ; one of them {Psophia) retains the bony superorbitals of 

 the Tinamou. 



I have hunted up every type of skull, available, in this family. The one most to my 

 pm-pose to compare with the small skull of Thinocorus was found to be that of the 

 Stanley Crane (Anthropoides stanleyanus) ^ — a bird of stature, and of the seed of the 

 giants. 



This type, next to Thinocorus, has the palatines widest apart ; next to it comes Eury- 

 pyga, and next to that the Weka Rail {Ocydromus australis). In the gigantic extinct 

 Rail {Aptornis defossor, Owen) the parasphenoid is very narrow, and the palatines as 

 much approximated as in the living Rallidse generally. (See Trans. Zool. Soc. vol. iii. 

 pi. Iii. fig. 3, a paper read on January 11th, 1848, where this bird is described as Binornis 

 casuarinue, Ow. ; and ibid. vol. vii., Jan. 1871, pi. xl. fig. 3, where this bird is termed 

 Aptornis defossor, Ow.). 



There are two characteristics in the adult Thinocorus which separate it from the ordi- 

 nary Pluvialine types (Charadriomorphse), namely: — the arrest of the basipterygoids ^ ; 

 and the absence of the lateral occipital fontanelles — vacuities shared by the Plover with 

 the Goose tribe, but absent even in the young of the Rails, and very variable in the 

 Gruidse. The small azygous occipital fontanelle of the Pigeon, which is variably closed- 

 in in the Sand-Grouse and Hemipods, is in Thinocorus wholly unenclosed, as in the 

 feebler forms of Plover — the foramen magnum being pear-shaped, and the narrow upper 

 part being due to deficient chondrificatiou in the embryo. 



In conformity with this divergence from the true Plovers, there is also the abortion 

 of the inner notches on the posterior margin of the sternum. In Eurypyga they are 

 almost suppressed, in the Rallidae quite ; whilst in the Cranes, in Psophia, and in the 

 Kagu there are no distinct notches whatever, external or internal. 



In some things, as I shall show, Thinocorus approaches the Hemipods ; with Quails 

 ' The gift of Dr. Murie. ' These are also aborted in (Edknemus and Otis. 



