'218 STRUCTURE AND CLASSIFICATION OF BIRDS 



from both the types already described, although the resem- 

 blances are on the whole closer to Aceros. 



The adductor longus is attached by two tendinous heads ; 

 the upper one of these, as inAceros, is attached to the lower 

 border of the femur ; this corresponds to the fleshy insertion 

 of the muscle in Bucorvus ; the lower tendon is fused 011 its 

 way with the inner head of the gastrocnemius, which is 

 continued upwards and reaches the femur, and then bifur- 

 cates into two tendons of insertion. The relations of the 







FIG. 101. LEG MUSCLES OF Aceros (AFTER BEDDARD). 



add, adductor ; St, semiteiidiuosus ; As/, its accessory ; Sm, semimernbranosus : 



/us/, gastrocnemius. 



semitendinosus and of the accessory semitendinosus are as 

 in Aceros nipalensis. 



In Toccus these muscles are much the same as in 

 Buceros. 



In Ceratogymna elata I find a closer resemblance to 

 Aceros than to any other of the genera mentioned in this 

 paper, but there is an agreement with Bucurviis in ih& fleshy 

 insertion of the adductor longus on to the lower border of 

 the femur. The accessory semitendinosus is distinctly double, 

 as in Aceros, and is attached by a short tendon to the 



