576 H. p. KJERSCHOW AGERSBORG 



into the gizzard does not harden in the alimentary canal. 

 The glandular structure of the epithelium of the liver exhibits 

 that it has an active function in vivo, owing to the presence 

 of a variable series of granules and vacuoles in the adjacent 

 cells fixed at the same time in the same way (PL 27, figs. 1, 2, 

 4, 7, PI. 33, 48-53). 



13. The heart consists of two chambers enclosed within the 

 pericardium. These chambers are separated by valves from 

 the efferent branchial veins and the afferent aortic trunk- 

 vessel. In the aorta, just below the valve of the ventricle, 

 is a blood-gland or node which contains pseudopodic cells. 

 The cells found on the outside of this node, i.e. within the 

 lumen of the aorta, are different in structure from those found 

 within the node (PI. 34, figs. 54-9). 



14, The wall of the heart consists of epithelioid and some 

 semi-musculofibrilloid cells (PL 34, fig. 59). 



15. The kidney is much branched, and is situated between 

 the pericardium and the gonadium. It communicates with the 

 pericardium through the renal syrinx which is closed at the 

 point of junction with the pericardium by what I have called a 

 c y n c i t i a 1 plate. The lining of the kidney is glandular ; so 

 is also that of the ureter, but neither is ciliated. The renal syrinx, 

 however, is ciliated. The cells of the renal syrinx are peculiar 

 in that the cilia are very large and independent in position, 

 i. e. they do not mingle with those of adjacent cells. The renal 

 syrinx is plicated, and from the cyncitial plate a ciliated villus 

 protrudes into the organ (Pis. 35 and 36, figs, 64, 65, 67, PI). 



16, The organs of reproduction represent an additional type 

 to the three types enumerated and described by Lang (1896). 

 The male and female ducts in M. leonina do not unite to 

 form a common atrium genitale as set forth by Lang for all 

 nudibranchs and a few tectibranchs, but open close together 

 through separate apertures (PL 37, fig. 77, M(jp) ; the penis 

 lies in front of the vagina (PL 28, fig. 9, P) ; in that way it 

 resembles the second type of Lang. Both genital ducts pass 

 independently to the same acinus ; in this respect it differs 

 from all three types of Lang, and, for this reason, I have 



