720 



MB. F. E. BEDIURD ON THE 



[Dec. 4, 



ance as diagnostic of the Monotreme heart than the fact of the 

 greater muscularity of the valve. 



This conclusion was obviously warranted by the facts discovered 

 by Prof. Lankester ; but the heart of Ornithorhynclms is more 

 variable, apparently, as regards this valve than would be inferred 



Kg. 2. 



Testis and vas deferens of Omithorhynchus. 



t, remains of testis, 

 .s, sac in which it is enclosed. 

 m, membrane attaching this sac to vas deferens (Sp). 

 », membrane attaching sperm-duct to body-wa 11. 



from Prof. Lankester's paper. The first of the two hearts which 

 I dissected was, at first sight, almost exactly like that figured by 

 Prof. Lankester in fig. 14 of plate xl. of his memoir. The muscle 

 " b " was single and there was a small membranous septal flap 



