BALLID^ BALLUS 243 



Family I. EALLID^. 



Aftershaft present in the contour feathers but rather small ; 

 fourteen or fifteen cervical vertebrae ; from ten to fourteen rectrices ; 

 all five Garrodian thigh muscles present ; deep plantar tendons 

 galline (see vol. iii, p. 2, fig. 2b). 



Genus I. RALLUS. 



Type. 

 Rallus, Linn. Syst. Nat. 12th ed. i, p. 261 (1766) ... E. aquaticus. 



Bill long and slender, the culmen longer than the middle toe 

 and claw ; no frontal shield ; nostrils elongated ovals, in a long 

 well-marked nasal groove, situated nearer to the base of the bill 

 than to the anterior end of the groove ; wings short and rounded, 



^^^^ggag^^HSOaSi 



Pig. 75. —Left foot of Ballus ccerulescens. x \^ 



the secondaries falling short of the primaries by very little ; tail 

 short, less than half the length of the wing ; tarsus shorter than 

 the middle toe and claw ; toes unwebbed. 



This is an almost cosmopolitan genus containing the Water 

 Bails ; about ten species are generally recognised, only one of which 

 is found in the African Continent, while another is known from the 

 Island of Madagascar. 



