236 



r. H. EDGEWORTH. 



to tlie cei'atoliyal, and those of the obliqui veutrales 11 and 

 III to the corresponding hypobranchials, whilst the IVth and 

 Vth meet their fellows in the median line, in the case of the 

 IVth also becoming attached to the basibranchial. The 

 parts of the first three branchial mj^otomes above the 

 Anlagen of the coraco-branchiales form adductors internal 

 to the branchial bars, and the upper portions of the obliqui 

 ventrales external to the branchial bars; in the case of the 

 fourth myotome only the upper portion of obliquus ventralis 



Text-fig. (iO. 



Rana, larva with hind legs moderately devek)ped. transverse 

 section. 



IV. The uppermost portions of the first four branrhial myo- 

 tomes form levatores arcnum branchialium ; in 8^ mm. 

 embryos the first is attached to the auditory capsule, the 

 second, third, and fourth lie outside the trunk myotomes 

 (Text-fig. 22) ; in 11 mm. embryos the upper ends of the third 

 and fourth have also shifted to the auditory capsule with addi- 

 tional attachments to the second pharyngo-branchial, and the 

 upper end of the second has become attached to the second 

 pharyngo-branchial ; all four are inserted to the correspond- 

 ing epibranchials. The trapezius is given off from the fourth 



