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and, beside returning blood from the lower jaw and tongue, 

 it also returns it from the muscles of the shoulder, tympanic 

 membrane, eye, nose, and the left side of the head generally. 

 This latter group of organs is in Rana* drained by a large branch 

 of the subclavian vein, called the cutaneous, but in Hyla aurea 

 the cutaneous (fig. 1, c.) does not reach much above the fore- 

 limb. 



It may also be noticed that the external jugular is not, as 

 in Rana, wholly made up by the mandibular and lingual veins, 

 but these are merely small branches joining on the main vein 

 as it comes from the side of the head. If the skin from the side 

 of the head be dissected off as in fig. 3 the small veins about 

 the head that unite to form the external jugular can be seen. 



The nasal vein (fig. 3, n.) runs from the external nares, near 

 the edge of the upper jaw, and unites with the main trunk of 

 the external jugular just at the angle of the jaws. 



The orbital veins (fig. 3, o.) join the nasal as it passes the 

 eye. They are usually two in number. 



The tympanic vein (fig. 3, t.) is a vein bringing blood from 

 the tympanic membrane. 



There is a vein bringing blood from the dorsal muscles of 

 the shoulder, and one bringing blood from the skin around 

 the shoulder and head, which also join the external jugular 

 near the angle of the jaws (fig. 3). 



2. The Innominate Vein (fig. 2, in.). — This is the second 

 and middle vein of the three that make up the left anterior 

 vena cava. It is a very short vein, and is made up of two main 

 branches — (a) internal jugular vein (fig. 2, i.j.), returning blood 

 from the interior of the skull and the • yeball, and leaving the 

 skull near the posterior border of the orbit ; (b) subscapular 

 vein (fig. 2, sa.) is a smaller vein than the former, and returns 

 blood from the region of the scapular bone. 



3. The Subclavian Vein (fig. 2, sub.). — This is larger than the 

 innominate, but much smaller than the external jugular. It 

 returns blood from the muscles of the shoulder and the fore- 

 limb. It is made up of the (a) brachial vein (fig. 1, br.), 

 which returns blood from the arm, and, after entering the body- 

 cavity, runs direct to join with the subclavian ; (b) the musculo- 

 cutaneous vein (fig. 2, m. and c, and fig. 1, c.) returns blood 

 from the skin posterior to the arms, and some of the muscles 

 of the shoulder. It does not, as in Rana, have anything to do 

 with skin anterior to the fore-limbs or the head. The musculo 

 vein returns blood from the muscles, and the cutaneous from 

 the skin, as before described. 



* Ecker's " Anatomy of the Frog," p. 244, fig. 161. 



