244 



Transaction* 



Supra-intestinal Vein. — The supra-intestinal vein runs forward from 

 near the termination of the intestine. It ends full in the portal heart. 



Subintestinal Vein. — Veins from the anterior ventral part of the 

 intestine unite to form a short subintestinal vein. The veins upon the 

 surface of the gall-bladder unite to form a cystic vein which joins the 

 subintestinal. The subintestinal vein then enters the right portal vein. 

 It does not carry blood through the liver direct to the sinus venosus, 

 as stated by Goodrich (hoc. cit.) for Myxinoids generally. 



The portal heart receives blood from three sources — the supra- 

 intestinal vein, the right anterior cardinal sinus, and the light posterior 

 cardinal sinus; while into the right portal vein there flows the sub- 

 intestinal. The portal vein, on leaving the portal heart, forks, right 

 and left veins passing to the corresponding lobes of the liver. These 

 branches enter the liver on the lower (concave) surface. 



EXPLANATION OF PLATES. 



Fig. 1. 

 Fig. 2. 



Plate XVI. 



Diagrammatic representation of the circulatory system. 



Part of the dorsal vessels and the nephridial system, from the dorsal aspect. 



a. Renal veinlet running from the dorsal aspect of a glomerulus to a seg- 



mental vein in the body-wall. 



b. Segmental artery sending branches to two glomeruli. 



Plate XVII. 



Fig. 1. 



The efferent branchial vessels and the anterior part of the dorsal aortic system, 



from the dorsal aspect. 

 The afferent branchial system, from the ventral aspect. 

 Right afferent branchial vessels, from the right side. 

 Anterior part of post-cardinal system, showing connection of right sinus with 



portal heart. 

 Fig. 5. The jugular system, dissected from ventral aspect. 



Fig. 2. 

 Fig. 3. 

 Fig. 4. 



a.l. Anterior lingual vein. 



at. Atrium. 



d.a. Dorsal aorta. 



e.b.t. Excurrent branchial tube. 



ef.br. Efferent branchial tube. 



g.s. Gill-sac. 



i. Intestine. 



i.i. Inferior jugular vein. 



i.b.t. Incurrent branchial tube. 



j.t. Combined jugular trunk. 



I. Lingual trunk. 



La. Left division of anterior aorta. 



l.a.c. Left anterior cardinal sinus. 



l.h. Left hepatic vein. 



l.j. Left jugular vein. 



l.n. Left nephridial system. 



l.p.c. Left posterior cardinal sinus. 



l.pt. Left branch of portal vein. 



l.v. Left division of ventral aorta. 



m.a. Median division of anterior aorta. 



oes.d. Oesophageo-cutaneous duct. 



p.l. Posterior lingual vein. 



ph. 



pt.ht. 



r.a. 



r.a.r. 



r.c. 



r.h. 



r.j. 



r.n. 



r.p.c. 



r.pt. 



r.v. 



s.a. 



s.i. 



s.v. 



sb.i. 



sq.v. 



spl.a. 



v. 



r.n. 



Pharynx. 



Portal heart. 



Right division of anterior aorta. 



Right anterior cardinal sinus. 



Communicating branch from right 



posterior cardinal sinus to portal 



heart. 

 Right hepatic vein. 

 Right jugular vein. 

 Right nephridial system. 

 Right posterior cardinal sinus. 

 Right branch of portal vein. 

 Right division of ventral aorta. 

 Segmental artery. 

 Supra-intestinal vein. 

 Sinus venosus. 

 Subintestinal vein. 

 Segmental vein. 

 Splanchnic artery. 

 Ventricle. 

 Ventral aorta. 



