TUBE OF PANTHALIS. 173 



animal's back, to the extremities of the parapodia, was 

 about T V; the two sides being approximately parallel, 

 excepting just at the two extremities, where the outline of 

 the body tapered off markedly. 



In a dorsal view were seen the two greyish-flesh 

 coloured palps, extending about T 5 g- of an inch in front of 

 the prostomium ; on either side of the palps, the cirri of 

 the first pair of feet were visible (appearing like antennas), 

 and apparently between the palps, two eyes, with reddish 

 stalks (between which is a minute tentacle) occasionally 

 peeped out from beneath the first pair of elytra. Except- 

 ing at the two extremities, where the elytra of the sides 

 meet and overlap, rather more than the central third of 

 the back was uncovered, the anterior part of its length 

 being of a pearly white, with a central pink stripe. 

 Further on it was flesh-coloured, due to the internal organs 

 being partially visible through the semi-transparent, finely 

 striated integument. The dorsal blood-vessel was most 

 striking. For the greater length of the body it undulated 

 just beneath the skin, and a beautiful red, bead like effect 

 was produced. About one third the width of the back, 

 on either side, is covered by the pearly-white, semi-trans- 

 parent elytra, the first few pairs of which are flat, and 

 the remainder campanulate. During life, these do not 

 rest upon the body, but in front are tilted-up, so as to 

 meet at an angle above the prostomium, the last few pairs 

 of elytra also assuming a similar position. Possibly this 

 rule may apply to the intermediate elytra, but I had no 

 opportunity of ascertaining this. 



A constant rising and falling of the elytra, as though 

 to facilitate the passage of water for purpose of respiration, 

 was observable, and the positions of the parapodia were 

 dimly indicated through them. Laterally, the anterior 

 portion of the animal was most interesting, as in addition 



