Anatomy of the Kingfishers. 105 



Kingfishers with reference to tliis point, and I paid minnte 

 attention to it as a character known to differ amf)ng King- 

 fishers. It is probahle that its presence is a Kingfisher 

 character; so far as I know, it is not fonnd in other birds, 

 and it seems too definite to have been acquired independently 

 in a number of cases. Its absence seems best explained as 

 a secondary loss. Beddard noticed that it was present in 

 one of two specimens of Sauropatis vagans; I found it 

 absent in one S. vagans and in S. chloris, but an apparently 

 degenerate slip represented it in -Sf. sancta and S. sordida. 

 It is absent in Alcedo ispida, but a diagonal slip represents 

 it in Alcedo asiatica and A. bengalensis. Assuming;, then, 

 that the loss is secondary, it appears that the eutaxic forms 

 Ceijx, Halcyon rufa, and H. pileata have lost it ; one of the 

 Alcedines has lest it, and in the others it is degenerate. In 

 Sauropatis it is present, absent, or degenerate ; in Ducelo it 

 is absent, in the other forms, entaxic or diastataxic, it is 

 present. Here, as in many other characters, there is not a 

 definite coincidence between entaxy and progressive change, 

 but the more general fact holds good that, where there is a 

 tendency within the group ior independent movement in any 

 direction, the eutaxic forms show a high relative average of 

 instances of such change. 



Latisshnus darsi, anterior et posterior. — The phylogeny 

 of these muscles outside the Avian group is an extremely 

 difficult problem, but I am on clear ground in stating that 

 the most common and generalized condition among birds is 

 the existence of an anterior and p(jsterior division, the two 

 being fairly equal in width and strength, well separated at 

 their origins, and in contact at their insertions. Such a 

 condition is well marked in all the diastataxic forms, 

 although there is a tendency, displayed in Dacelo and in 

 Sauropatis, for the anterior division to be weaker than the 

 posterior. I follow Fiirbriuger in rej,arding any well-marked 

 divergence from the condition described as secondary. Among 

 the Col'.uubidae I found the divt'rgent tendency to be in the 

 direction of reduction of the posterior division, and this was 

 well-marked among the euta.\ic forms. In the Kingfishers 



