628 Sir W. Jardine on the Ornithology of the Island of Tobago. 



it is as follows : — " Ce qui prouve que cette piece, analogue a 

 Podonto'ide, est dans le fait le corps de Pallas, c'est que dans la 

 Matamata elle se soude aux trois premieres, et prend toute la 

 forme d'une vertebre, s'articulant avec l'axis, et pourvue, comme 

 lui, en dessous d'une crete longitudinale, et sur les cotes de pe- 

 tites apophyses transverses." — Tome v. part ii. p. 207. 



In the Matamata [Chelys fimbriat a) I find the piece answering 

 to the first wedge-bone in Enaliosauria, and to that which Cuvier 

 (/. c. p. 96) describes as representing the body of the atlas in the 

 Crocodile, articulating but not confluent with the large odontoid, 

 and articulating also with the fore-part of the base of the neural 

 arch of the atlas. Traces of the suture still exist between the 

 rest of the neural arch of the atlas and the ' odontoid/ The 

 Emys (Cimochelys) longicollis resembles the Chelys in the size and 

 shape of the central part of the body of the atlas. The difference 

 between these and other Chelonia in respect to the odontoid, re- 

 lates essentially to the greater proportion of the neural arch of 

 the atlas which it supports, concurrently with its larger size. 

 I have the honour to be, Gentlemen, 



Your obedient servant, 



Richard Owen. 



London, October 16, 1847. 



XXXI. — Horn Zoologies. By Sir William Jardine, Bart., 

 F.R.S.E. & F.L.S. 



[Continued from vol. xix. p. 83.] 



Birds of Tobago. 



Vireo gilvus, Vieill. n.* 



Mr. Kirk has appended no note to this species, which from the 



small number of specimens received does not appear to be very 



plentiful. 



Siurus aquaticus, Swain. Gray-throated Wagtail. N. 

 ■" Very little is known of this active and restless little bird ; they 

 are in general to be found in the bed or channel of rocky rivers, 

 or. by waterfalls, and when surprised will fly to a considerable 

 distance, making a noise similar to that of the European { Stone- 

 chatter/ After alighting they continue to bob up and down the 

 heads, uttering a ' chirk ' at every motion, at other times run- 

 ning along the sand nimbly in the manner of the Sandpipers. 

 Feeds on small insects like gnats and ants." We have also 

 received this species from Jamaica. 



* Species marked n. are also found in North America ; s. in South Ame- 

 rica ; and n. s. in both. 



