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PROFESSOR W. C. WILLIAMSON ON THE ORGANIZATION 
PLATE 18. 
Fig. 41. A slightly tangential transverse section of a Traquaria. a. Wall of 
the capsule. b. Tubular spines, e. Investing tissue. Enlarged 150 
diameters. 
Fig. 42. Transverse section of a young example, displaying a double inner mem¬ 
brane, f f, the latter occupied by numerous cells. Enlarged 150 
diameters. 
PLATE 19. 
Fig. 43. Small portion of the capsule-wall of Traquaria seen near its inner surface. 
a. Sections of free portions of five tubular spines, b. Bases of tubular 
spines, close to the capsule-wall. Enlarged 200 diameters. 
Fig. 44. Part of fig. 43. Enlarged 660 diameters, a. Small mucronate projections 
of the exterior of the tubular spines, giving off branching and interlacing 
tubular (?) threads, which spread through the investing substance, fig. 
41, e. a'. Coalescing portions of several tubular branches. 
PLATE 18. 
Fig. 45. Transverse section of a specimen of Traquaria with more rigid tubular 
spines, a. Capsule-wall. b. Spines with openings at the points corre¬ 
sponding with the murications of figs. 40 and 41. e. Investing substance. 
f An inner membrane containing numerous large cells, g. Enlarged 113 
diameters. 
Fig. 46. Transverse section of a crushed specimen, a. Shattered capsule-wall. 
b. Muricated spines, b'. Crushed and broken spines hnbedded in the 
investing substance, f An inner membrane splitting into two at f'. 
f". A yet more internal membrane, with numerous flattened circular 
prominences. Enlarged 113 diameters. 
Fig. 47. The tubular spine, b, of fig. 46. Enlarged 240 diameters, a. Bases of 
broken off tubular branching processes like those seen at a , a'. 
PLATE 19. 
Fig. 48. Portion of the internal membrane, f", of fig. 46. Enlarged 660 diameters. 
f. Flat-topped areolae, each surrounded by a circular depression, f", and 
forming the summits of corresponding prominences, f 
Fig. 49. Part of a transverse section of a Traquaria, showing tubular spines 
branched at their summits, b, and expanded at their bases, a, a, a", a ", 
into numerous branching tubules, hi contact with the capsule-wall. 
e. Investing substance. Enlarged 322 diameters. 
Fig. 50. Fragments of four tubular spines, exhibiting the murications of the preced¬ 
ing figures developed into branching tubes b, b'. Enlarged 340 diameters. 
