90 



HIROSIII OIISIIIMA : 



those found in tentacles. 



Calcareous ring. — Composed of small pieces. Radial segment 

 (a, MVR), 19 mm. long and 5 mm. broad, giving off long posterior 

 prolongations consisting of a number of small segments. Interradial 

 segment (RVI and LVI), measuring 5.5 — 7 mm. in length and 

 2 mm. in breadth, is usually made up of two pieces. 



Retractor muscles. — Inserted to body-wall at a distance less than 

 one-sixth the body-length from the anterior end. 



Polian vesicle. — Usually single, hanging in the left dorsal in- 

 terradius, 1 1 — 24 mm. long. In one specimen an accessory vesicle of 

 5 mm. length was found in the left ventral interradius. 



Stone-canal. — 4 mm. long, provided with a minute madreporite. 



Digestive tube. — Taking the course usual in the subfamily. 



Respiratory trees. — Two, one in each dorsal interradius, of a 

 length exceeding five-sixths the body-length. 



Genital tubes.' — -Attached to the mesentery in the same manner 

 as in Pscudoatcumis àfrìcanus and Pliyllophoriis cucwuiformis 

 (Semper) [Ludwig 25, p- 813], viz., in two lines of 30 mm. length 

 along the middorsal line. Each tube measures 5 mm. long and is 

 dichotomously branched. 



Remarks. — The presence of twenty tentacles made me hesitate 

 somewhat in identifying the specimens at once with Orcula liypsipyrga. 

 But I see the tentacle number of that species is still in a very 

 doubtful state. v. MaRENZELLER has given it to be fifteen from a 

 much contracted specimen, while THÉEL has found thirteen tentacles, 

 and Seuiter has given no account of the number. A careful re- 

 examination of those specimens in that respect is very much desirable. 

 Sl.UITER's statement (cited before) with regard to the elongated disk 

 of tables in pedicels does not agree with what I have observed in my 

 specimens, as it probably does not also with the state of the thing in 

 v. Marenxe leer's and TllÉEE's specimens. After all, I think my 

 specimens may well be held to be specifically identical with those of 



