92 



BULLETIN OK THE BUREAU OF FISHERIES. 



Tin afferent vessels (fig. 18, pi. i). The afferent branchial arteries, as a rule, 

 run some distance on the gill arches before branching to the gill filaments. At 

 a point where the split ends of the efferent arteries join to form a single vessel, the 

 afferent artery gives off a recurrent branch (1, fig. 18) which runs between the two 

 efferent vessels and branches to the most ventrally situated gill filaments. Beyond 

 this point the afferent vessel occupies a position lateral to the efferent trunk. 



Fig. 3.— Cranial portion of the arterial system in the hickory shad (Pomolobus mediocris). Ventral aspect, natural size. 

 ih. efferent branchial arteries have their ventral ends reflected on the right side and cut off short on the left. 



FIG. i - Second efferent branchial artery in the hickory shad, viewed from front, showing arrangement of efferent ves- 

 sels. Natural size, 



Fio. 5.— Fourth efferent branchial artery in the hickory shad, riewed from front, showing arrangement of efferent vessels 

 on arch; filamentar vessels not shown. 



BRANCHES OF THE EFFERENT BRANCHIAL ARTERIES. 



Tin first efferent branchial artery (i, fig. 16, pi. i). This artery gives off 

 the following branches, which will he described in the order named: A. The hyoidean 

 artery. B. The direct afferent pseudobranchial artery. V. A small vessel which 

 lies dorsal to the gills. D. The carotid artery. 



A. The hijniihii i, artery (->')" arises about l' cm. from the ventral end of the first 

 branchial arch, and pursues a course chiefly following the hyoid arch ultimately- to 

 reach the pseudobranch. Passing mesocraniad along the first branchial arch, it 



"The hyoidean artery has been described by former writers under a number of different names, such as .1. hyoideo- 

 ujwrcuJarii (Miiller, 1839), i hyo-opercularis (Owen 1866 , A. hyo^nandibalarit (Maurer, 1888 



