130 



branchial, pseudobranchial and carotid arteries in the adult Amia calva. 

 These arteries have already been somewhat fully described in larvae 

 of this fish (Allis, 1900, and Weight, 1885), and certain of them 

 have been briefly referred to, or more or less fully described, in the 

 adult (Allis 1897, Parker and Davis 1899), but none of these de- 

 scriptions are sufficient for my present purpose. I have accordingly 

 had dissections made, for this special purpose, of the head of an adult 

 specimen of this fish. The head used for this purpose had been long 

 preserved in alcohol, but it was found easy to trace the arteries by 



a.cer 



aaI7 



Ihbr mhbr ta 



Fig. 6. Diagrammatic representation of the arteries shown in Fig. 5, 



injecting them with India ink, the injections being repeated as the 

 dissections progressed. 



In this one adult Amia (Fig. 5 and 6) the afferent arteries to 

 the first pair of branchial arches arise at the anterior end of the 

 main truncus arteriosus, but between the roots of these arteries a small 

 median vessel has its origin and, running forward as a prolongation 

 of the truncus arteriosus, soon separates into two parts each of which 

 is the primary afferent artery of the hyoidean arch of its side. At 

 interbranchial distance posterior to the first pair of afferent branchial 



