THE SYSTEM OF PHYLLOPHORIN.-E. 



»5 



in position, only 2 mm. long and liable to be overlooked in the 

 contracted state. 



Calcareous deposits. — Except in introvert, tables arc quite 

 sparsely scattered in all parts including the wall of pedicels. Their 

 disk (tcxtfig. 6, b — e) is usually of a roundish outline with smooth 

 or rarely serrated margin, the diameter varying within a range of 

 0.05 — O.09 mm. They are more or less regularly perforated by a 

 large central hole and eight or more peripheral holes. Over the 

 central hole there is spanned a cross-shaped arch, from which arise 

 four rudimentary pillars of 0.02 mm. height (f). The pillars but 

 seldom branch on top and there form an incomplete toothed crown 

 (c and g). Rosettes are profusely found iu introvert and anal region, 

 but in a very small number in tentacles and pedicels. They are 

 oval in general outline, measuring 0.02 — 0.06 mm. in the longer 

 diameter. End-plates are well developed, their diameter varying 

 from 0.15 mm. to 0.4 mm. in accordance with the size of pedicels. 

 Around the end-plate there are found a number of elongate perforated 

 plates or supporting buttons without knob (h). At tip of tentacles 

 there are found delicate supporting rods ( i ) in very thinly scattered 

 distribution. They measure 0.04 — 0.O9 mm. in length and are 

 provided with one or two holes at both ends. Rudimentary anal 

 teeth consisting of a loose calcareous network are present. Anal 

 papilla; are supported by irregular perforated plates. 



Calcareous ring. — Radial segment (a, RVR and MVR) 13 — 17 

 mm. long and 2 mm. broad, with the anterior margin divided into 

 two unequal halves by a deep notch (a). Posterior prolongations 

 composed of about six pieces. Interradial segments (RVI) 8 — 12 

 mm. long and 1.5 — 2 mm. broad, each composed of several pieces. 



Retractor muscles. — Inserted at different levels, the midventral 

 one most anteriorly. In the specimen represented in fig. 3, Pl. I., 

 those of the dorsal pair are inserted to respective radial muscle at a 

 distance of five-elevenths, those of the ventral pair at that of two- 



