NOTES ON SO^fE BKITISII NUDIBRANCIIS. 377 



Museum at Newcastle-on-Tyne I have found the following notes on the 

 living animal : — 



"The foot exhibited beautiful dendritic markings.* The glands in 

 the papillte are considerably branched. The animal yields a quantity 

 of mucus, has a strong sugar smell, and is sluggish in its motions. The 

 papilla; are remarkable for their rhythmical pulsations. They dilate and 

 contract simultaneously between thirty and sixty times a minute. The 

 contraction is very forcible, the posterior surface of the papill* being 

 most contracted. This pulsation has all the appearance of being con- 

 nected with the circulation. The papilke are much depressed when in 

 a state of contraction." 



The colour of the preserved specimens varies from white to yellow, 

 with darker mottlings on the back and upper side of the cerata. The 

 variations in shade are considerable. Sometimes the ground colour is 

 yellowish and the mottlings light, leaving a general impression of 

 yellowish brown. Sometimes the mottlings are thick and dark and the 

 ground colour opaque white. The upper surface then appears to be 

 purplish black, with a few white markings. 



The animals are stoutly built, the largest specimens measuring 

 5'5 mm. by about 3'5. In front the dorsal surface is bare, the cerata 

 being set only at the sides, but behind they close over the body. The 

 foot is white, broader than the body, with an expanded margin, but 

 rather straight in front. No anterior groove is visible. 



At the sides there is a groove between the body and this margin, so 

 that the body, though narrower than the foot, partly overhangs it. On 

 this lateral projection of the body are set the cerata in three not 

 very regular longitudinal rows. As a rule only two rows are fully 

 developed, and the third, which consists of smaller cerata, has the 

 appearance of being crowded in. The total number of cerata on either 

 side does not appear to exceed fifteen, which is less than the number 

 shown in Alder and Hancock's plates. The cerata are somewhat ovate 

 in shape. Those behind are larger and more inflated than those in 

 front. They contain ramified hepatic diverticula which bear primary 

 and sometimes short secondary branches. 



The head bears on each side a rounded prominence, but there are 

 neither rhinophores nor tentacles in the ordinary sense. The anus is 

 on a prominent papilla in the medio-dorsal line and nearly terminal. 



There is no trace of jaws. The radula is ascoglossan and short, 

 containing five or six teeth in the ascending, and about as many in the 

 descending portion. In an irregular heap lie about seven teeth of 

 varying size, and with them a mass of minute spines, apjiarently repre- 



* Due ajipareiitly lu tlic ramilied diverticula of tlie alinientiiry canal being seen through 

 the semi-transparent sole. 



