REPORT OX THE HOLOTHTJRIOIHEA. 
97 
Genus Orcula, Troschel, 1846; Semper, 1868. 
(?) Orciila hypsipyrga, von Marenzeller, 1881 (PL V. fig. 6). 
Habitat. — Station 233a, May 19, 1875 ; lat. 34'" 38' N., long. 135° 1' E. (Japan); 
depth, 50 fathoms ; sand ; a single individual. 
The specimen obtained by the Challenger Expedition has a length of about 
120 mm., thus being much larger than the specimen described by von Marenzeller. 
The posterior extremity of the body is much more tapered than the anterior, and is 
destitute of any teeth. The colour in alcohol, is reddish or yellowish, brownish -grey, with 
the sucking-disks of the pedicels white. The pedicels are scattered all over the ambulacra 
and interambulacra, and do not present any arrangement in rows ; they are slight^ 
more numerous on the ventral surface than on the dorsal. The perisome is thin and 
phable, but its surface is rough from the outwardly directed spires of the tables. The 
tentacles are small and completely withdrawn into the body, and therefore I am not able 
exactly to state their number and position ; I counted only about thirteen tentacles. 
The five radial pieces of the calcareous ring (PI. V. fig. 6, a) consist of several smaller 
parts and are prolonged posteriorly into two long processes, the narrow ends of which 
are joined to the corresponding ends of the adjacent pieces, exactly as stated by von 
Marenzeller. The interradial pieces are simple, without posterior prolongations. The 
length of the radial pieces is about 1 7 mm. A single madreporic canal and Polian vesicle 
are present. The retractors communicate with the longitudinal muscular bands near 
the anterior extremity of the body. The reproductive organs are well developed, and 
their tubes are about 20 mm. long, and slightly branched. The respiratory organs attain 
nearly the length of the body itself, and their branches are short and not very numerous. 
Excepting the well-developed terminal plates of the pedicels, the perisome contains 
only calcareous tables (PI. V. fig. 6, h) consisting of a more or less irregularly rounded, 
or even angular disk, wfith about twenty holes in it, and a spire composed of four, seldom 
more, rods, which are several times transversely connected. The spire is more or less 
conical, terminating in a single point or in several spines ; its length is about 0T4 mm. 
To judge from the description of von Marenzeller, the tables in the type-specimen 
have more holes in the disk than is generally the case in those of the specimen brought 
home by the Challenger Expedition. No other difference seems to exist. 
Genus Phyllophorus, Grube, 1840. 
(?) Phyllophorus incompertus, n. sp. (PI. V. fig. 8 ; PL VIII. fig. 5). 
Body in contracted state ovate, about equally rounded at each extremity. Mouth 
closed by five prominences, each formed by three to six or more small papillm vfith 
black retracted tops. Anus surrounded by very minute, almost inconspicuous 
(ZOOL. CHALL. EXP. — PART XXXIX. — 1886.) ^4 
