C. L. Edwards 
257 
prong forks (Fig. 45, a variafce with 5 prongs and 5 vertical rods), and these 
branches grow toward one another while the vertical rods rise higher and the 
centre of the fundamental rod becomes elevated (Fig. 46). The outer branches 
grow together and unite to form the primary and peripheral holes of the disc, while 
the distal ends of the vertical rods are joined by transverse beams to build the 
crown, and then the teeth begin to appear (Fig. 47). Finally the last cross-beam 
is added to complete the crown and spire, the last peripheral branches fuse to form 
the disc, the teeth enlarge and the normal table is completed (Figs. 48, 49). 
2. Structure of the Table. 
The typical table consists of a disc perforated by 4 larger, primary holes 
extending toward the centre alternating with 4 secondary holes of medium size in 
the periphery (Figs. 49, 64 — 97). Generally there are one or more (range 1 — 9) 
smaller tertiary holes in between the secondary and forming with them a peripheral 
circle (Figs. 57 — 62). The bars between the primary holes bend upward, so that 
the centre of the disc is elevated, and at the same time it supports a spire consist- 
ing of 4 vertical rods united distally by cross-beams to form a crown (Fig. 49). 
The crown bears at each of its 4 corners, 3 teeth ; 2 horizontal, diverging at 
right angles, each continuing the axis of a cross-beam, and the 3rd perpendicular 
to the plane of the others (Fig. 75, the positions of the underlying vertical rods 
shown by dotted circles). 
3. Variation in Grown and Vertical Rods. 
Among the 234 tables of H. floridana 5 have a triangular crown (Fig. 79) 
supported by 3 vertical rods; 5 have the crown arrested in development, the 
central hole not formed and with only 3 vertical rods (Fig. 80), and 4 have the 
normal 4 vertical rods but with the crown incomplete on one side. Three have 
spires with 5 vertical rods. 
The number of teeth varies from 6 to 16, the largest number being represented 
in Fig. 78. Sometimes odd teeth project from the middle of the cross-bars 
(Figs. 76, 77, 83). There are 5 crowns in each of which 1 tooth is bifid at the tip ; 
2 crowns with 2 teeth bifid ; 1 crown with 6 teeth bifid ; 1 crown with 7 teeth 
bifid and 1 crown with 1 tooth trifid. 
Not included in the statistical series of H. floridana are several interesting 
variations. Fig. 81 shows a triangular crown without a central hole ; Fig. 82, 
a partly formed crown hole ; Fig. 86, an incomplete crown with 3 teeth bifid 
and 5 supporting rods; Fig. 87, a complete disc with 5 rods and no crown; 
Fig. 88, the disc, and Fig. 89, the crown, of a table with 7 rods ; Fig. 90, from 
above and Fig. 91 from below, a depressed abnormal form. 
b. Tables of Bivium and Trivium in H. Floridana. 
For the study of these tables data were taken from 14 Holothurids representing 
various places scattered over the Florida-Caribbean region. When possible the 
Biometrika vi 33 
