594 EGBERT SCHARFF. 



Oil a new move it feels its way first by means of the prosio- 

 mium, which seems to act as a tactile orgau^ and then repeats 

 the same performance. Sometimes it coils itself round in a 

 snake-like fashion, continually using the thick lower lip, which, 

 I believe, may also be useful in nutrition although I have not 

 actually seen it taking up food with it. 



The Skin. — This is composed of an epidermis covered by a 

 very thin homogeneous cuticula. The outlines of the compo- 

 nent cells are not very readily made out in cross sections, and 

 they vary in size according to the different parts of the skin in 

 which they are found. At the sides of the body their height 

 is about equal to their breadth, towards the ventral side. On 

 the other hand, the cells increase in height and decrease in 

 width. Their appearance here will be referred to again in con- 

 nection with the nervous system, which lies in its entire length 

 in the epidermis ; suffice it to say that it appears to consist of 

 several layers in the ventral part of the body. 



I said before that the under surface of the head segment is 

 ciliated. The same has likewise been noticed in the other two 

 species of Ctenodrilus, as well as in a few more kindred forms. 



A surface view of the skin under very high power reveals a 

 large number of the dark violet pigment spots, and among 

 them a few much lighter ones. The intervening spaces are 

 partly covered by exceedingly dark minute specks, contrasting 

 with the light green or yellow ground. According to KenneP 

 the dark pigment is dissolved out by alcohol, a fact which I 

 can testify by my own experience. The same author says, p. 

 380, that if this fatty matter be withdrawn from the cells by 

 the action of alcohol and turpentine, the colouring material 

 remains behind in shape of irregular stains. The dark pigment 

 lies in the epidermal cells, and appears to be of a fatty nature. 

 In the prostomium and around the anus it is largely developed, 

 and in these parts almost fills up the whole of the cells. This 

 condition does not obtain towards the middle of the body, 

 where the pigment only enters to a small extent into the 



^ J. Kennel, " Ueber Ctenodrilus pardalis," 'Arbeiten aus d. Zool. 

 Institut, Wurzburg,' 1882, p. 380. 



