1896.] ME. R. LYDEKKBR ON THE SEA-OTTEtt. 235 



Nijctieorax c/riseiis may serve as a typical Heron upon Xvhicli to 

 harig the description of such slight divergences from the normal 

 as exist. Reckoning as the last tracheal ring that from which the 

 pessulus arises in front, the intrinsic muscles, which are narrow 

 ■and do not fan out much, are attached to the third bronchial 

 semiring ; on the posterior aspect of the syrinx the last tracheal 

 ring is incomplete, the pessulus being attached to the one in front. 

 The widest bronchial semirings (seen laterally) are the third and 

 fourth ; tliey are also the last ossified ones. I can detect no differ- 

 ence in ArcUa cinerea, A. cocoi, A. ac/ami, A. candidissima, Nycti- 

 eorax violaceus, and Tiyrisoma hrasiliense. In Ardea hidoviciana 

 each muscle is much fanned out and almost divided into two 

 ■muscles, of which one is inserted near to hinder border of rings. 



6. Additional iSTote on the Sea-Otter. 

 By R. LydekkeRj F.R.S. 



[Eeoeiyed January 10, 1896.] 



In reference to my note on the Sea-Otter (Latax lutris), published 

 in the Society's Proceedings for 1895 (p. 421), I have received 

 another coniniunication from my correspondent Mr. H. J. Snow, 

 •of Tolfohama. He therein tells me that I have misunderstood the 



Sea-Otter in walking posture. 



meaning of his statement that "the hind flippers are doubled 

 back." lu interpreting this as meaning that they were bent 



