86 



IIIROSIII OIISIIIMA : 



sevenths, ami the unpaired midvcntral at that of two-ninths the 

 length of same from the anterior end. In another specimen the same 

 distances were respectively two-fifths, a quarter and one-fifth the 

 length of the radial muscle in relation. 



Polian vesicle. — Usually single, situated in the left dorsal 

 interradius, 5 — 10 mm. long. In one specimen two vesicles were 

 found hanging together in the same interradius. 



Stone-canal. — Situated on dorsal mesentery, 1.5 — 3 mm. long, 

 provided with a minute madreporite. 



Respiratory trees. — Two, each running along the whole length of 

 dorsal lateral interradii. 



Genital tubes. — In bundle on both sides of dorsal mesentery, 

 about 7 mm. long, once or twice dichotomously dividing. 



From the foregoing remarks, the present species may be 

 diagnosed as follows : — 



Body usually spindle shaped in contracted state ; length up to 

 65 mm. Color of general perisome uniformly brown, or with purple 

 patches. Tentacles twenty in number, of three different sizes : ten 

 large, five medium-sized, and five small. Pedicels scattered all over 

 body surface, somewhat more numerous on ventral than on dorsal 

 surface ; zonal arrangement sometimes recognizable. Integument soft, 

 with very sparsely scattered tables showing a large central hole anil 

 eight or more smaller peripheral holes in the disk, and four low 

 pillars which may sometimes unite with one another at top. jVVell 

 developed end-plate and rudimentary anal teeth present. Introvert 

 provided with rosettes only, similar deposits being also found in anal 

 region and in a small number in pedicels and tentacles also. Tip 

 of tentacles provided with delicate rods. Both radial and interradial 

 segments of calcareous ring consist of several small pieces. Radial 

 segment with long posterior prolongations and three anterior notches. 

 Polian vesicle single, situated in left dorsal interradius. Stone-canal 

 small. Genital tubes in two tufts, once or twice branched. 



