ANATOMY OF THK SHOE-BILL. 681 



Ilio-femoralis internus (^rectineus). — Strong, little fleshy slip 

 from the A^entral edge of the preacetabular portion of the ilium to 

 the back of the femur below the neck. As in most birds. 



Femori-tihiales {Crmxeus and Vastus). — The external muscles 

 are fused to form a common mass ; the vastus internus is large, 

 iirising from nearly the whole length of the femur. 



Ca^ul-ilio-femoraUs (Femoro-caudal). — This is a broad thin 

 strap of muscle arising fleshy from the femur (text-fig. 129, FE.C) 

 and running upwards and backwards under the biceps and be- 

 tween the semitendinosus and the semimembranosus and passing 

 to the underside of the tail, where it becomes a thin tendon 

 spreading out into a sheet which meets its fellow of the other 

 side, the combined insertion being to the tendon of the depressor 

 ■coccygis where that is inserted to the ha^maj^ophyses of the 

 posterior caudal vertebrae. There is no accessory femoro-caudal. 

 The accessory fem.-caud. is, I believe, invaiiably absent in Stega- 

 nopods, Herons and Storks, although it is j^i'esent in Spoonbills 

 and the Flamingo. The fem.-caud. itself tends to be degenerate. 

 It is usually present in Storks, but is very slender in Dissura and 

 absent in Leptoptilus ; it is weak in the Herons and absent in 

 .several genera. 



Caud-ilio-flexori'us {Semitendinosibs and Accessory semitendi- 

 nosus). — Origin fleshy from the ischium behind the biceps and 

 extending on to the fascia posterior to the ischium ; meets the 

 rather small but distinct accessoiy or femoral head in a tendinous 

 raphe, and the combined muscles are inserted to the middle belly 

 ■of the gastrocnemius (text-fig. 130, C.Il. 1 & 2). The muscle is 

 much weaker than the semimembranosus. 



Ischio-Jtexorius {Seminievibranosus). — This is the usual broad 

 strap underlying the semitendinosus, and in this case mucb 

 thicker and wider than the latter. It has a wide origin from the 

 lower edge of the ischium and the fascia over the obdurator 

 externus, is unconnected with the semitendinosus, but receives a 

 .strong tendinous slip (text-fig. 130, SI.) from the inner adductor 

 and then is inserted to the tibia by a flat tendon. 



Gastrocnemius. — There are the usual three heads of which the 

 tibial head is the strongest. The outer head arises from the 

 ■external condyle of the femur in common with the short arm of 

 the biceps sling (text-fig. 129, Gas.). The middle head is the 

 smallest and arises from between the condyles of the femur by a. 

 flat tendon. The tibial head is enormous and arises from the 

 tendon of the ilio-tibialis and from the cnemial crest of the tibia. 

 The three heads unite in the usual way rather less than half-way 

 down the leg to form the tendo achillis. 



Relations of the Caud-ilio-Jiexorius, Ischio-fiexorius., and Gastro- 

 .cnemizis. — Weldon (38) called attention to the varying relations 

 of these muscles and the difierences they presented in Storks, 

 Ducks, and Phoenicoptertis. I have noted them in a number 

 of Storks and Herons and paid a good deal of attention to 

 them in Gruiform and Limicoline Birds (31 & 32). With 

 minor variations as to the precise interconnections of the 



