BLOOD-VESSELS OF MUSTELUS ANTARCTICUS. 
693 
8. The oviducal arteries (in the female). 
9. The posterior spermatico-mesenteric artery. 
a. The posterior spermatic arteries. 
b. The posterior mesenteric artery. 
10. The renal arteries. 
11. The (torso-lumbar (segmental) arteries. 
12. The iliac arteries. 
a. The femoral arteries. 
b. The posterior lateral arteries. 
13. The caudal artery. 
A. Arteries arising from the Efferent Branchial Arteries. 
(1.) The pseudobranchial and anterior carotid arteries. 
a. The pseudobranchial artery. 
Arterienstamm der Spritzloch-Nebenkieme, Muller (17). 
Abfiihrendes Gefdss cler Spritzlochkieme, Hyrtl (11). 
b. The anterior carotid artery. 
Carotis anterior v. Carotis interna anterior , Muller (17). 
Carotis anterior, Stannius (25). 
Carotide interne, Milne Edwards (14). 
Zufiihrendes Gefdss der Spritzlochkieme, Hyrtl (11). 
The course of these vessels has already been briefly described (p. 690). They are 
considered together because, although one is the afferent and the other the efferent 
trunk of the pseudobranch, they are practically continuous even in forms like Mu.stelus 
and Raja, in which the pseudobranch is present, while in those species— e.g., Callo- 
rhynchus (fig. 17) —in which the mandibular gill completely disappears, they form a 
single vessel to which the name anterior carotid is applied. 
The application of the name “ carotid ” to the cephalic arteries of fishes must of 
course be taken to imply nothing more than a general correspondence with the 
similarly-named vessels in the higher Vertebrata. In Sauropsida and Mammalia the 
external carotid is formed from the ventral ends, the internal carotid from the dorsal 
ends of the aortic arches, the former supplying the head generally, the latter the brain 
and eye. In Plagiostomes the artery here called posterior carotid is, from its mode of 
origin, better entitled to the name “ internal ” carotid than any other vessel, and the 
mandibular artery to the name “ external ” carotid. As regards their distribution, 
however, it will be seen that these two arteries jointly perform the function of external 
carotid, while that of internal carotid is assigned to the artery now under considera¬ 
tion, the “ anterior ” carotid of Muller. 
These considerations make it desirable to drop the names “internal” and “external” 
