326 



FISHES 



CHAP. 



FIG. 192. Venous system of Proto- 

 pterus. a, Auricle ; a.c, anterior 

 cardinal ; an.v, anastomotic veins ; 

 c, intestine ; f.v, femoral or iliac 

 vein ; g. b, gall-bladder ; h.p.v, hep- 

 atic portal vein ; i.j.v, inferior 

 jugular ; ov.v, ovarian veins ; p, 

 pericardium ; p.c.v, left posterior 

 cardinal ; p.v', parietal or segmental 

 veins ; s, stomach ; sb.v, subclavian. 

 Other reference letters as in Fig. 

 191. (From Newton Parker.) 



limb each femoral vein divides 

 into two branches ; one of these 

 forms a renal portal vein as previ- 

 ously described ; the other, which 

 may rightly be termed a pelvic 

 vein (pv.v), unites with its fellow 

 to form a median anterior ab- 

 dominal vein (a.ab). Pursuing its 

 course forwards in the ventral ab- 

 dominal wall, the vein eventually 

 reaches the heart and opens into 

 the sinus venosus. The direct 

 connexion of the anterior abdo- 

 minal vein with the heart is yet 

 another example of the retention 

 in the adult Neoceratodus of a 

 transitory embryonic feature in 

 the developing Amphibian. 1 



As in other Fishes, the blood 

 from the head is conveyed to the 

 Cuvierian ducts by an anterior 

 cardinal and an inferior jugular 

 on each side. There are no 

 lateral veins, the blood from the 

 pelvic fins flowing into the renal 

 portal system or into the anterior 

 abdominal vein, and that from 

 the pectoral fin through sub- 

 scapular and brachial veins into 

 the Cuvierian ducts. Lateral 

 cutaneous veins are, however, 

 present ; and, as in Elasmobranchs 

 (e.g. Mustelus antarcticiis), anas- 

 tomose anteriorly with the sub- 

 scapular vein and behind with the 

 caudal vein. 



1 As an abnormality the adult Frog may 

 retain the embryonic connexion of the 

 right anterior abdominal vein with the 

 heart (Buller, Journ. Anat. and Phys. iii. 

 1896, p. 211). 



