EEPORT ON THE HOLOTHUEIOIDEA. 
189 
C-shaped rods, however, seem to be absent in this species (?). With regard to the 
arrangement of the pedicels, Selenka says that the pedicels of the odd ambulacrum 
and those forming the inner row on the two lateral ventral ambulacra are twice 
as many as those in the remaining rows. Semper, on the contrary, remarks 
that the ventral pedicels in his species are more crowded than those on the dorsal 
surface. These differences must be more plainly illustrated. 
Labidodemas dubiosum, Ludwig, 1875. 
The ventral “ pedicels ” and the dorsal “ papillae ” arranged in double rows along the 
ambulacra. Deposits — rare, irregular, oval buttons; tables with the disk small, 
almost annular, and with the short spire built up of four rods and one transverse 
beam, and having the top terminating in about five long, simple (or bifurcate) spines. 
Habitat . — Tahiti (Ludwig). 
This species does not seem to be well defined from the preceding ones. 
Genus 2. Stiehopus, Brandt, 1835. 
Tentacles eighteen to twenty. Ambulacral appendages in the shape of pedicels and 
papillae ; the former arranged in three more or less distinct longitudinal series on 
the ventral surface ; the latter mostly situated on the tops of larger or smaller 
protuberances, forming rows along the dorsal ambulacra, or scattered all over the 
dorsal surface. Two bundles of genital tubes, one on each side of the dorsal 
mesentery. Anus devoid of calcareous teeth. C-shaped deposits often present 
in the perisome. 
A. C-Shaped deposits present. Tentacles eighteen or twenty. 
1. Dorsal ambulacral apioendages 2 '>'^’'esent only on the' ambulacra. 
a. Deposits — C-shaped bodies ; and tables of one kind consisting of 
a smooth, rounded, perforated disk, supporting a spire of four 
rods and one transverse beam ; the truncated apex of the spire 
terminating in several teeth. 
Stiehopus chloronotus (subgenus Perideris), Brandt, 1835 ; Selenka, 1867 ; Ludvdg, 
1881, 1882. Stiehopus cylindricus, Haacke, 1880. 
Tentacles twenty. Papillae on rather prominent conical warts, forming a double row 
along each dorsal ambulacrum, and a zigzag or double row along each side of the 
body. Spire of the tables terminating in eight to twelve teeth. 
Habitat . — Zanzibar (Selenka), Querimba and Mozambique (Semper), Indian Ocean 
(Ludwig), Mauritius (Haacke, Ludwig), Macassar (Ludwig), Lugunor and Guahan 
(Brandt), Sandwich Islands (Selenka), Pulo Tikul, Nicobar Islands, 1 elew Islands^ 
I 
