THE SEA-SLUGS. 



259 



the environment of the protected animal, and must have a 

 direct relation to this environment. It seems probable that 

 the sliminess of many sea-slugs, like that of some worms, 

 may render them unpalatable to many foes. 



Much smaller than Dendronotus, but in its way quite as 

 beautiful, is Doto coronata, a little animal occasionally 

 found among corallines at the margin of the rocks. (The 

 animal is shown in Fig. 4, p. 13, and the spawn in Fig. 75.) 

 If you can pick it out from a dense cluster of the weed, you 

 may natter yourself that your eye has been tolerably well 

 trained. One specimen may be found by chance, but if you 

 are desirous of obtaining several for examination, you will 

 find the need of patience exceeding that of Job. Place 

 your specimens on green weed or in a light dish, and you 

 may wonder at their conspicuousness, put them back among 

 the corallines and zoophytes and they seem to disappear 

 from sight. Not only is there no definiteness of form, no 

 difference of colour to catch the eye, but the colours are so 

 arranged as to give that contrast of reddish pink and white 

 so eminently characteristic of 

 tangled tufts of coralline. 

 The body is very small, with 

 a pale ground colour and 

 crimson markings; there are 

 no gills, but the back bears 

 five to seven pairs of very 

 large papilla, each of which 

 is covered with large tubercles, 

 whose crimson colour stands 

 out against the light tint of 

 the papillae. The papillae are 

 often described as resembling 

 pine cones, and their shape 

 and markings give them an 

 apparent bulk out of all pro- 

 portion to the size of the 

 body. In confinement they 

 are very apt to fall off at the slightest touch. The tentacles 

 are very slender and spring from large trumpet -shaped 

 sheaths. The animal lives on zoophytes and is strictly an 

 inhabitant of deep water. I do not know the special value 



Fio. 75. Spawn of Doto coronata. 

 After Alder and Hancock. 



