346 MESSES. F. E. BEDDA.RT) AND P. CHALMERS MITCHELL [May 7, 



Fig. 2. 



Heart of Alligator, opened to disjilay the right ventricle and the origin of 



left aorta, 

 a &b. Two rows of rudimentary valves, the row opposite b being shorter and 

 having a deep pit under the lowest of three chief rudimentary valves. 



c. Septal flap of right auriculo-ventricular valve; the membranous area is 



dotted, and a strong muscular band ties down the lower end of the flap 

 to the septal wall. 



d. Fleshy half of right auriculo-ventricular valve . 



e. Muscular band tying down junction of two flaps, and corresponding to 



bridge in bird's heart. 



