NUDIBRANCHIATA OF THI^ L.M.B.C. DISTRICT. 141 



motion. The colour of the hepatic caeca in the cerata is 

 from a bright brick-red to vermiUion and is quite opaque ; 

 while the surrounding integument (" sheath " of Alder 

 and Hancock) is colourless and transparent. There is 

 a ring of opaque white pigment on the surface near the 

 apex (PI. VIIL fig. 1, pg.) The cerata are placed indis- 

 tinctly in rows which are placed very close together and 

 are 18 to 20 in number. There are about 6 cerata in each 

 row, the smallest being as usual on the outside. Some 

 of the smaller cerata have little or no colour, and in one 

 of our specimens we found one of the largest cerata near 

 the middle of the body to be perfectly clear and colourless 

 — apparently the hepatic caecum was absent. 



The hepatic caeca in this species are very distinctly 

 lobulated (PL VIIL figs 1, 3, 4 and 5). In some cases it 

 might be said that short branches are present, thus lead- 

 ing in the direction of the distinctly branched caeca of 

 Doto. Figure 3 shows one of the cerata of Cori/jjhella 

 rufihranchlalis in longitudinal section and exhibits the well 

 marked lateral lobes or short branches of the caecum, while 

 fig. 5 shows the condition, and arrangement of the red (r) 

 and yellow {y) pigmented masses, in part of a slightly 

 squeezed living specimen. 



The broad ring of superficial pigment near the tip of the 

 cerata hides the greater part of the cnidophorous sac (PI. 

 VIIL fig. 1, py.) allowing only the apex and the wide 

 base to be seen. The sac is large and of elongated pyri- 

 form shape, and has a very muscular w^all. The cnidocysts 

 are long and narrow and rather numerous. They nearly 

 meet in the centre of the sac (PI. VIIL fig. 4, c.c.) The 

 connecting tube between the cnidophorous sac and the 

 hepatic C{©cum is so short as to be reduced to a mere 

 opening (see PL VIIL fig. 1, surface view, and fig. 4, 

 section), on the edges of which the smaller basal cnidocysts 



