1890.] ANATOMY OF PODICA SENEGALENSIS. 429 



differeuces between the condition of this muscle in the Rallidce and 

 that in the Coh/inhidce and Podtcipedidcti. 



The two latissimi dorsi muscles are shown as regards their 

 insertion in the accompanying figure (Plate XXXIX. fig. 4) ; as is 

 generally the case among birds, the posterior of the two muscles 

 (which are hardly distinguishable in the middle of their course') 

 ends in a long thin tendon below the fleshy insertion of the other. 

 It seems, from Prof. Fiirbriuger's account [4] of the posterior 

 latissimus dorsi, that its origin from the front border of the ilium is 

 very inconspicuous among the rulicaria3 ; indeed it was not observed 

 at all in many cases. In the Colymblda, on the other hand, this 

 muscle has an extensive origin from the anterior border of the 

 ilium ; Podica is in this particular Colymbine and not Halline. 



The two rhomboidei have an extensively aponeurotic origin. This 

 appears to be so far evidence in favour of the Colymbine affinities 

 of the genus, since these muscles seem to have less tendon among 

 the Eails ; this is certainly the case with Gallinula chloropus, which 

 I dissected for the purposes of comparison along with Podica. 



The sevratus j^osterior has a very large tendinous insertion on the 

 end of the scapula ; in Gallinula chloropus this muscle is fleshy up 

 to its insertion. 



The ambiens is present and has the usual relations. 



The semitendinosus is a powerful muscle ending in a muscular 

 insertion covered by an aponeurosis. 



There is no accessory semitendinosus. 



The origin of the tensor faseice extends behind the acetahiilum. 



The biceps is very large and important, with a somewhat unusual 

 mode of insertion ; it is of course covered by the tensor fascia ; when 

 that muscle is cut across and turned back the biceps is seen to arise 

 from the whole of the postacetabular region of the ilium. It has 

 no less than three insertions : — (1) By a broad flat muscular insertion 

 on to the fascia covering the outside of the leg ; this strip of muscle 

 springs from the outer side of the biceps just behind its division 

 into the second and third insertions. (2) By a thickish long tendon 

 which corresponds to the tendon of insertion in most birds ; this 

 passes in the ordinary way through a loop and is i,nserted some way 

 down the leg. (3) The muscle divides just after the branch to the 

 fascia of the leg into two branches, of which one has the insertion 

 through the biceps loop that has just been described ; the other 

 branch forms a long thin muscle which becomes tendinous just before 

 its insertion on to the leg some way below the second insertion. 



This singular modification of the biceps cruris (which is illustrated 

 in Plate XXXIX. fig. 2) appears to be, so far as our present 

 knowledge enables us to speak, quite unique among birds ; it recalls 

 in many respects the biceps in the Mammalia, though I have not 

 the faintest desire to make any comparison with other groups : 

 nothing seems to me to be more unreasonable than to compare 

 muscles from one large group of animals to another ; although I am 



' Their origins are closely side by side, aud there is no space between, as there 

 is, for examjilc. in Gallinida chloropus. 



