2;^o The Irish Naturalist. becembef , 



sea-weed Cladophora rupestris which floated m the dish 

 and begin to feed on it earnestly, their mouths closely 

 adpressed to the twigs as they stripped off the succulent 

 surface-layer. Others, within half an hour of their emer- 

 gence, were seen to float, foot upward, on the water-surface, 

 and one to hang suspended from it by a slime -thread. In 

 fact, the infant Actaeonias showed all the savoir faire of 

 the experienced adult. 



The largest of the twelve, measured as soon as it had 

 emerged and begun to crawl, was found to be almost i mm. 

 in length, the smallest was little more than half that size. 

 In colour, all of them were pale translucent amber, flecked 

 with brown pigment, the eyes were very distinct and placed 

 far back from the front of the head, and the whole body- 

 surface was coarsely tubercular or warty. Under strong 

 illumination the action of feeding could be followed with 

 ease. The characteristic ascoglossan radula, forming two 

 unequal sides of a triangle with the apex pointing forwards, 

 was visible through the transparent muzzle or snout in 

 front of the eyes and was seen to work to and fro, as the 

 mouth, laying hold of the Cladophora, made a series of 

 rapid invaginations or gulps. Now and then a minute 

 fragment of the green sea-weed was torn off and this frag- 

 ment could be seen travelling down the oesophagus and on 

 to the hepatic region. So ravenously did the young Actaeo- 

 nias feed that within an hour of their emergence, their 

 bodies, at first light amber in colour, became so vivid a green 

 as to render it hard to distinguish the animals from the 

 sea-weed. When thus gorged with food the hepatic branches 

 appeared as coarsely granular, the green matter not being 

 evenly distributed along them, but disposed in separate 

 bead-like masses. In the intervals of feeding, the animals 

 changed colour from green to yellow, as the food became 

 digested or was discharged. 



By the 31st March the opaque white spots, which in 

 the adult form a lateral interrupted line along each side 

 of the body-surface above the hepatic trunks, began to 

 appear. By the 21st April some of the young animals 

 had grown to a length of 2 mm., and showed very distinct 

 though blunt head-appendages. By the 30th April, one 

 had grown to a length of 3 mm., and the yellow masses of 



