THE SYSTEM OF rilYLLOPHORINTE. 



Si 



two pillars which unite with each other but once, forming four 

 teeth at apex. Height of spire is usually about 0.05 mm., but may 

 reach 0.08 mm. near and in the tentacles ( e ). In the general 

 perisome the tables are incomplete, changing into irregular perforated 

 plates of various shape as figured by v. Marenzeller [Fig. 9, a]. 

 Tentacles supported by somewhat irregular tables and perforated rods 

 as well as by a few rosettes. Peculiarly modified tables of the form 

 of a tripod, described by v. MARENZELLER and MlTSUKURl as 

 supporting pedicels, I could find only in the pedicels located in the 

 anteriormost parts. End-plate of pedicels imperfect and small, con- 

 sisting of irregularly branched rods ; its diameter varying within a 

 range of 0.14 — 0.15 mm. 



Calcareous ring (a) is 40 mm. long, and is composed of numerous 

 small pieces as is well known. Retractors inserted on body-wall at 

 different points of radial muscles : those of dorsal radii inserted in the 

 middle of the length of the contracted body, those of ventral lateral 

 radii at a distance from the posterior end equal to about eight- 

 thirteenths the length of the respective radial muscle, and the mid- 

 ventral retractor at a distance from the posterior end of more than 

 two-thirds the length of the arched midventral radial muscle. 



A tubular Polian vesicle, 38 mm. long and 30 mm. in diameter, 

 hangs on the circular canal in the left dorsal interradius. Stone-canal 

 7 mm. long, with an ellipsoidal madreporite about 1 mm. long. The 

 third limb of intestine runs along the left side of the midventral 

 radial muscle. The respiratory tree in each dorsal lateral interradius 

 extends nearly throughout the entire body-length. 



5. JPhyllophovus fragilis Mitsukuri & Oiisiiima, sp. n. 



(Pl. I., fig. 3 ; textfig. 6). 

 In his manuscript the late Professor K. MlTSUKURl provisionally 

 considered this species to be new and described it as follows : — 



"Specimens examined. — 12 specimens from Sakibaru near Naha, 



