65 



G.). Henee (lie kidneys tend to diverge posteriorly. 

 I hey are triangular in shape, the longest side being 

 external. As they are wholly independent of one another, 

 they differ from the kidneys of Sepia, where the two are 

 in direct communication. The ureter is situated half way 

 down the external side of the sac, and bears the urinary 

 aperture at the tip (fig-. 37, Ur. p.). When fresh, the 

 intestine, heart, liver, etc., may be seen through the 

 transparent walls of the urinary sacs. On opening the 

 kidney it is found to contain a thick colourless liquid in 

 which may be seen yellowish accretions of guanin -both 

 the liquid and the guanin being excretory products 

 eliminated from the blood by the glandular cells of the 

 kidney. Roundish colourless corpuscles are found floating 

 iu the kidney fluid, and also numbers of the small 

 Mesozoan parasite, Dicyema miilleri, in various stages of 

 development (PL X, fig. 81). Behind the kidney run the 

 lateral venae cavae, and the two abdominal veins, and 

 Avhere these vessels touch the kidney wall they are 

 produced into the club-shaped venous appendages. The 

 kidney wall, which elsewhere is quite smooth, membranous 

 and non-glandular, is composed of columnar glandular 

 cells where it covers these appendages. As shown (1 J 1. 

 VII, tig. 56), these " spongy bodies " have their surfaces 

 furrowed by numerous folds and grooves, lined also by 

 the glandular excretory epithelium of the kidney. The 

 visceral mass dorsal to the kidney also protrudes into, 

 and so encroaches on, the cavity of the sac. The ureters 

 are canals about 12 mm. long, and are furrowed 

 longitudinally on their inner surface. 



The Pericardial gland is a white gland of somewhai 

 depressed oval form, situated on the inner anterior wall of 

 the branchial heart, and enclosed in the pericardium 

 (fig. 40, Br. app.). Numerous folds run inwards from the 



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