ZooL.— Vol. II.] ROBERTSON— ENTOPROCTA. 325 



those stolons forming the outer border, and from the seg- 

 ments of any of the interior stolons. By this means a mat- 

 ted growth is produced which makes it impossible to tease 

 out a colony without breaking it into small fragments. Fig- 

 ure I represents two stolons united for part of their length. 

 It is not uncommon, however, to find four or more firmly 

 united together. The stolon is segmented but not always 

 to the extent that Ehlers considers characteristic of the 

 PediceUinidge. Non-polypide-bearing segments {non. -pi. 

 seg-.) occur, alternating with segments which bear poly- 

 pides; but this is not the invariable rule. Polypides are 

 frequently found upon successive segments, as is shown in 

 the stolon extending to the right (fig. i, sue. seg:). This 

 drawing may seem to indicate that polypides are found 

 upon successive segments only at the growing ends of sto- 

 lons. This condition, however, is not confined to young 

 stolons, but is found in older parts of the colony also. As 

 an illustration of the variability of stolonic segmentation 

 presented by the species, I would say, that in twenty cases 

 in which this point could be determined with certainty, 

 twelve showed an intercalated non-polypide-bearing seg- 

 ment, while in eight cases, the polypides grew upon suc- 

 cessive segments. 



2. The Polypide. — Each polypide consists of an un- 

 branched holosarcine stalk, and a calyx. There is consid- 

 erable difference in the height of the various individuals 

 which form a colony. Of ten polypides, all of which are 

 adult so far as the functioning of the digestive organs are 

 concerned, the smallest measures 0.64 mm. in height, and 

 the tallest, 3.60 mm. The average height of the ten is 

 1.90 mm. The extreme mobility of the calyx, the obhquity 

 of the tentacular region, and the spininess of both stalk 

 and calyx are very conspicuous features of a colony. 



In the retracted position, the stalk is usually much 

 curved, the calyx being then brought face downwards, and 

 the convex surface of both bristles with a formidable array 

 of spines (figs, i and 2). Although I have not had an 

 opportunity to examine living specimens, I cannot but 



