A bietineae (?) from the Cretaceous of New Zealand. 1 1 3 
Medullary rays In transverse section are numerous and conspicuous 
(see PI. IV, Fig. 1), and chiefly 1-5 tracheides distant. They are nearly 
all uniseriate , with a few exceptions where the rays are partly biseriate. 
They vary from 1 to 24 cells in vertical height. In 100 counts the most 
frequent heights were: 3 cells high, 11 per cent. ; 4 cells high, 14 per cent. ; 
s. 
Text-fig. i. Planoxylon Hectori , sp. nov. Small portion of transverse section, s., spring 
elements in which three rows of pits in the radial wall can be seen, xp., pits in the greatly thickened 
late-formed wood, par., parenchyma cell between spring and last-formed elements, mp., pits in the 
horizontal wall of medullary ray cell, e., end walls of medullary ray cells. [Slide No. 52823 a, 
British Museum (Nat. Hist.).] 
7 cells high, 14 per cent. ; 9 cells high, 10 per cent. ; while rays above 
16 cells high amounted to 3 per cent. only. The rays therefore are low for 
so old a trunk. The cells of the ray are all of one kind. 
Details of elements . Tracheides . The large, square, elements of the 
spring wood average about 40 x 50 to 50 x 55 \i In diameter. They have 
rather thin walls (see PI. IV, Fig. 1, and Text-fig. 1). In their radial walls 
the three rows of pits are often seen in transverse section (j., Text-fig. 1). 
I 
