REPORT ON THE POLYZOA. 191 



The stems are arranged alternately, with great regularity 

 on opposite sides of the stolon. There is a swelling at the 

 junction of the stolon with the stem-basal cylinder of Hincks, 

 which, in this case, is wider than in the one figured in 

 B. M. P., and the muscular substance is continued for a little 

 distance on each side into the stolon. Then about the 

 middle of the stem is another swelling, and just under the 

 head a third, which is constricted so as to have the appear- 

 ance of two swellings, both muscular, and the lower one 

 rather less than the upper one. It is easy to see that these 

 swellings would be of great use to the creature in giving 

 it a variety of movements in order to search for food and 

 to retreat in face of danger. 



It is possible that the individual without the medial 

 swelling may be an imperfectly developed form so far as the 

 stem is concerned. How the median swelling has been 

 formed I do not know, but it is quite possible that the head 

 swelling may be converted into the median one by an elonga- 

 tion of the stem above it. I am the more inclined to this 

 view since, in some individuals, there is a short stem between 

 the uppermost swelling and the head, and the part of the 

 stem above the median swelling varies much in size, while the 

 part between the base and middle swelling is pretty constant 

 (PI. Ill, fig 2). 



There is little doubt, I think, that it should be referred 

 to P. gracilis, yet the characters mentioned above show it to 

 be a well marked and very aberrent variety, for which I 

 propose the name, var. nodosa. 



Family II. — Loxosomid^. 

 Not recorded in our area. 



Explanation of Plate III. 

 Fig. i. Eucratea chelata, var. elongata, nov. 

 Fig. 2. Pedicellina gracilis , var. nodosa, nov. 



