AORTIC ARCHES OF BIRDS — GLENNY 



583 



modified vpiitral carotids and is in accord with Hughes' (1934) 

 observations in the chick embryo. 



In Zanclostomus javanicus and Phaenicophaeus pyrrhocephalus 

 both dorsal carotids arc superficial and do not enter the hypapo- 

 physial canal (infranormales) , but lie on either side of the oesophagus 

 to which organ they supply blood (A-3). Meckel (1826) suggested 

 that this arrangement of the carotids might be expected in some 

 species of bird. 



A still further modification in the arrangement of the dorsal caro- 

 tids is found in a specimen of Rhamphococcyx curvirostris erythrognathus 

 (USNjM 223471). In this specimen the left dorsal carotid serves as 

 a much-reduced ascending oesophageal artery, while the right dorsal 

 carotid is reduced to a small ligament which enters the hypapophysi- 

 al canal (A-3-s/A-4-d) ; the right superficial cervical artery sends off 

 branches to the oesophagus. 



Yet another modification of the bicarotid arrangement is found in 

 Bhopodytes viridirostris. In this species, both dorsal carotids are 

 reduced to ligamenti ottleyi which enter the hypapophysial canal 

 (A-4). 



In each of the above mentioned species, the vertebrals and super- 

 ficial cervicals were notably enlarged and appeared to carrj^ an 

 increased amount of blood to the head region. 



Species studied 



By Bhaduri and Biswas 



Eudynamis s. scolopaceus = Eudynamys 

 s. scolopacea (Linn6) 



By Garrod 



Cuculus canorus Linn4 



Cacomantis variolosus sepulcralis (S. 

 M tiller) 



Chrysococcyx sp. 



Phaenicophaes sp. = Phae7ncophaeus py- 

 rrhocephalus (Pennant) 



Guira piririgua— Guira guira (Gmelin) 



Centropus senegalensis (Linn6) 



By Glenny 



Cuculus sp. 



Cacomantis pyrrophanus schistaceigu- 



laris Sharpe 

 Chrysococcyx cupreus intermedius Hart- 



laub 

 Chalcites lucidus layardi (Mathews) 

 Surniculus lugubris (Horsfield) 

 Urodynamis taitensis (Sparrmann) 



Coccyzus erythrophthalamus (Wilson) 

 Coccyzus cinereus Vieillot 

 Coccyzus americanus (Linn6) (2) 

 Piaya rufigularis (Hartlaub) 

 Saurothera merlini d'Orbigny (2) 

 Ceuihmochares aereus (Vieillot) 

 Rhopodytes viridirostris (Jerdon) (A-4) 

 Rhinortha chlorophaea (Raffles) 

 Zanclostomus javanicus (Horsfield) (A- 



3) 

 Rhamphococcyx curvirostris erythrog- 

 nathus (Bonaparte) (A-3-s/A-4-d) 

 Phaenicophaeus pyrrhocephalus (Pen- 

 nant) (A-3) 

 Crotophaga ani Linn6 (3) 

 Guira guira (Gmelin) (2) 

 Tapera naevia chochi (Vieillot) 

 Geococcyx calif orniana (Lesson) 

 Neomorphus geoffroyi salvini Sclater 

 Coua caerulea (Linn^) 

 Centropus bengalensis javanensis (Du- 

 mont) 



