MILLER— CONTRIBUTIONS FROM ANATOMICAL LABORATORY. 225 



of these branches, the Submaxillary Vein, Sbm., PL 11, is 

 formed by branches from the antero-ventral wall of the oral cav- 

 ity and the anterior portion of the lower jaw. The vessel thus 

 formed passes along the ventral edge of the submaxillary bone, 

 receiving in its course a number of branches from the ventral 

 side of the head and from about the gill arches. About 4 mm 

 posterior to the angle of the mouth this vessel unites with the 

 naso-orbital to form the external jugular vein. From this point 

 the external jugular vein runs posteriorly between the digastric 

 and masseter muscles. In this part of its course the external 

 jugular is just beneath, and closely applied to, the skin ; it ap- 

 pears here as a sinus, the Jugular Sinus, J. S., PI. 11, and re- 

 ceives numerous branches from the lateral and dorsal portions 

 of the head ; the largest of these branches is formed by the union 

 of small branches from the temporal and masseter muscles. 

 Just where the gills join the branchial cartilages this sinus runs 

 ventrally for a short distance, then posteriorly and empties into 

 the Duct of Cuvier external to the place where the subclavian 

 vein enters. Just before making this last turn it is joined by 

 the internal jugular. 



The Lingual Vein, Li., PI. 11, is formed not only by 

 branches from the tongue, but also from the digastric, the cera- 

 tohyoid and the geniohyoid muscles. Prom its origin it runs 

 posteriorly along the gill arches until it reaches a point lateral 

 to the Duct of Cuvier; it then turns towards the median line 

 and joins the subclavian vein just before it empties into the 

 Duct of Cuvier. 



The Lateral Vein, L., PL, 11, arise near the median region 

 of the body wall and run anteriorly along the lateral line. Just 

 external to the Duct of Cuvier it turns from its position beneath 

 the skin and, passing towards the median line, joins the Duct 

 of Cuvier external to the entrance of the posterior cardinal. 

 The lateral veins are formed from branches which join them at 

 right angles from the septa in the abdominal muscles. These 

 branches may form an anastomosis with the veins which pass 

 into the liver, along the ventral mesentery, from the body wall. 



