102 
THE VOYAGE OF H.M.S. CHALLENGER. 
Length of the largest individual, 35 nam. Pedicels in simple zigzag rows along 
the ambulacra. Two ventral tentacles smaller. Calcareous ring, like that in 
Cucwftlaria hyndmanni and Cucumaria elongata, devoid of posterior prolongations. 
Deposits — more or. less regularly formed, knobbed, perforated buttons ; and 
minute cups. The buttons are of a roundish form and unequal in size, in 
number of holes and knobs ; commonly the rounded knobs are rather prominent. 
Some of the buttons are of considerable size, almost plate-like, with numerous 
holes and knobs. The cups are in want of a true rim, the ends of the 
dichotomously branched curved arms or spokes, which constitute the cups, being 
never, or only seldom, connected with each other. Pedicels supported by per- 
forated rods of the shape figured by Diiben and Koren. Colour, whitish. 
1). Deposits — oval knobbed buttons with four holes and undulated 
margin; larger plate-like ones with at least one complete 
circlet of smaller holes round the four central ones, and with 
uneven or knobbed surfaces. 
Cucumaria vicaria (Ocnus), Bell, 1883. 
Pedicels in pairs, like the typical forms of this group of Cucumaria, but so irregular 
that they present a zigzag arrangement in each ambulacrum. Some of the 
deposits attain to a great size ; the smaller are developmental stages of the larger. 
The pieces of the calcareous ring delicate, without posterior prolongations (?). 
Habitat. — Antarctic Sea (Bell). 
c. Deposits — slightly irregular, oval or oblong buttons, with a smaller 
number of holes, with knobs or spines, and with one end drawn 
out into a considerable spine or dentate perforated process. 
Cucumaria leonina, Semper, 1868. 
Body ovate. No anal teeth. The oblong buttons have, according to the figure 
given by Semper, about seven holes, two smaller of which are situated in the 
narrower dentate end. Even the knobs seem to be few, though about twice as 
many as the holes. Calcareous ring devoid of posterior prolongations (?). 
Habitat. — Singapore (Semper). 
Cucumana miniata {Cladodactyla, subgenus Polyclados), Brandt, 1835; Selenka, 1867 ; 
Ludwig, 1881. Pentacta miniata, Stimpson, 1857. (?) Cucumaria albida, 
Selenka, 1867. Cucumaria fallax, Ludwig, 1875. 
Body cylindrical. Anus surrounded by five small radially disposed plates or teeth. 
Calcareous ring not very weU developed, without posterior prolongations (?). 
Deposits like those in Cucumaria leonina. 
Hohitat. — Alaska (Ludwig), Sitka (Brandt), California (Selenka). 
