Mr. Yarrell on the Anatomy of Birds of Prey. 181 



external. The head is narrower than the following segment, and 

 on each side are the black reticulated prominent eyes., which do 

 not touch the external margin, and are not perfectly round ia 

 their circle. The segments of the body are sliort, transverse, con- 

 vex, and nearly equal, those towards the tail being rather the 

 narrowest. They are seven in number, and bear each a pair of 

 legs. These are six-jointed, and the tarsal joint is armed with a 

 stout claw and a smaller inner one. The two first joints are 

 nearly equal, the third and fourth are shorter, while the two 

 succeeding are again a little lengthened. The inner surface of 

 the whole, except the first, is clothed with short soft hairs ; a 

 tuft of hairs is placed on the middle of the external side of the 

 second joint, another at the base of the third, and a few hairs at 

 the base of the fourth. The tcnl consists of one large segment, 

 rounded behind, obliquely truncated at the sides. The lamelloe 

 of the caiuUd b/fid process are equal, of a linear oval shape, neither 

 ciliated nor serrated. The animal swims with considerable 

 velocity, and often on its back. It contracts itself into a ball 

 when alarmed ; and it can live a considerable time out of the 

 water. It agrees in almost every respect with the description of 

 the S. rugkauda given by Dr. Leach, with this exception ; — in it 

 the body is said to be smooth^ in ours it is granulated ; and per- 

 haps the term roughs which is applied to the rugkauda^ may not 

 be synonymous with granulated, which more properly character- 

 izes the species we have attempted to describe. 



Berwick, Augiisi 12, 1826. 



Art. XVIl. Some Observations on the Anatomy of the 

 British Birds of Prey. By William Yarrell, Esq. 

 F.L.S. 



[To tlie Conductors of llie Zoological Journal.] 



Gentlemen, 



If the following remarks on some peculiarities observable in 

 the species of the first two genera of British Birds, have sufficient 

 novelty to recommend them to a place in your Journal, they are 



