25 291 



The aorta crosses obliquely over the ventral face of the front end of the first 

 vertebra, in the furrow seen on the lirst corpus (PI. I, fig. 11**), to the left side 

 where it is lying along the coalesced corpora, keeping up this asymmetrical posi- 

 tion to the end of the body cavity, where it enters the subvertebral caudal canal. 



The arteria coeliaca originates from the aorta a short way behind the entrance 

 of the last branchial vein (or arteria revehens) ventral ly where the arteries to the 

 pectoral fins leave laterally; it passes to the right side of the oesophagus below 

 the front end of the air-bladder and further along the right side of the stomach, 

 giving off branches to the latter, the airbladder and the liver; at the gall- 

 bladder it gives branches to the "red body" and follows the same course as the 

 portal vein and biliary duct on to the front end of the pyloric appendage, where it 

 still follows along the appendix with the biliary duct to the end of the latter 

 and then separates from the portal vein, each of these vessels occupying in their 

 further course backwards opposite faces of the intestine; in the mesentery of the 

 hind part of the latter the arteria coeliaca leaves the intestinal wall and passing 

 obliquely through the mesentery enters the dorsal body wall between the two 

 gonads and anastomoses with the aorta. 



The right cardinal vein is very large; imbedded in the right part of the 

 kidney it enters from behind the coalesced part of the vertebral column, lying to 

 the right side of the corpora, and receiving branchlets across the corpora from the 

 opposite side, one for each vertebra. The left cardinal vein is wanting altogether. 

 Along the left side of the coalesced vertebræ, imbedded with the aorta in a silvery 

 sheath, a small vein runs forwards, anteriorly crossing over the right cardinal vein 

 and going to the head. Small veinlets passing through the nerve-holes of the 

 coalesced vertebræ join the right cardinal vein and the small "vertebral vein" on 

 the left side. No branches from the aorta seem to enter the nerve-holes. 



The kidneys are coalesced into one body reaching from the hind end of the 

 body cavity to the last of the coalesced vertebræ. This body contains two symmetri- 

 cally arranged urinarj' ducts, thus proving the originally paired condition of the 

 kidneys. The ducts unite to a common, very short part opening as usual behind 

 the (female) genital pore; there is no urinary bladder. 



Dorsally over the front end of the air-bladder, just below the anterior end 

 of the first vertebra, a small pyriform body is found on the left side, but nothing 

 corresponding to it on the right side. I suppose it to be the remnant of the left 

 pronephros, and a silvery thread, going backwards from it, I assume to be the 

 rudiment of the pronephric duct (the condition of the old spirit material was such 

 that a histological examination would scarcely give any reliable information). 



Along the outer side of the aorta, dorsally to the air-bladder, runs the left 

 vagus-nerve accompanied by the left sympathetic; the right vagus and the right 

 sympathetic follow in a similar manner the right vena cardinalis; from the vagus 

 and spinal nerves and probably also from the sympathetic branches are given oil' 

 to the wall of the air-bladder. 



D. K. D. Vidensk. Selsk. Slil-., 7. Hii-kke, naturvidensk. og ni;illiem. Afil, VIII. ."j. 38 



