266 
Holothuria floridana 
the trivium Tyipe B has a mean diameter of 288^ with a range of 255 /t — 315 /it. 
Type B occurs in 42 of the dorsal appendages and in only 6 of the ventral. 
Type C, with the smaller holes toward the centre (Fig. 6), or with larger, 
irregular holes (Fig. 7), in the bivium, has a mean diameter of 182 ^ with a range 
of 120 [jb — 195 /A, and in the trivium occurs but once with a diameter of 210 /i. 
The most degenerate form in this species is Type D (Fig. 8) with a diameter of 
90 /i. It only occurs once dorsally and not at all ventrally. 
d. SuppoKTiNG Rods. 
1. Dorsal. 
In the dorsal appendages supporting rods are present in 14 (15'9 %), absent in 
44 (50 7o) and not determinable in 30 (•34'1 Those especially characteristic 
of the papillae (Figs. 10, 11, 12) form a series of rib-like structures, from rods only 
very slightly curved and with a few spines at each end (Fig. 10) to those more 
bowed and spinous with the ends slightly branched (Fig. 11). Occasionally a rod 
is found either straight, or curved, with the ends expanded and from 1 to several 
holes in addition to the spines and branches. Fig. 13 presents a rare variate in 
the form of a rosette with a few large holes. The tentacles have supporting rods 
similar to the series described above for the papillae. In the tentacles the rods 
are confined to the branched ends and are not found in the stalks. 
2. Ventral. 
The ventral supporting rods (Figs. 20 — 22) are especially characteristic of the 
pedicels and so may be found with these appendages in the bivium. The most 
completely developed (Fig. 22) is a rod straight, or slightly curved, with a hole in 
each expanded end. Terminal prongs may grow out (Fig. 21), and then these 
may branch and their ends unite to form several holes at each end (Fig. 20). 
Connecting links (Figs. 18, 19) to the perforated plates (Fig. 17) of the body-wall 
can be found, lying particularly toward the base of the pedicel. So far these 
ventral supporting rods have not been found in their typical form in the dorsal 
pedicels. In some Holothurids they seem to be missing from the ventral pedicels. 
The curved rib-like rods of the papilla, in their typical form, are not found in the 
pedicel. 
e. Association of Forms of Ambulacral Appendages with Types of 
End-plates. 
In the analysis of the characters of the pedicel and the papilla it is necessary 
to show which characters are associated together. The following data are from 
the dorsal region. Of the appendages with Type A of end-plate 32 (78"5 °/„) are 
cylindrical, none conical and 9 (219 Y^); '^ot determinable. This type may be 
considered as typical for the completely established pedicel. The association of 
Type B is not determinable in 21 cases (58"3 "/oX since the remaining 
15 (41*6 °/^) are with cylindrical appendages and none with conical, it may be 
