HYALONEMA (OONEMA) BIANCHORATUM PINULINA. 317 
upper part of the stalk imbedded in the sponge-body are not centrotyle am- 
phioxes. The largest one observed was 7 mm. long. 
The acanthophores (Plate 83, figs. 1-35) are normally composed of one 
to six rays. One quite abnormal one (Plate 82, fig. 24), which I found in speci- 
men a, has two long and six more or less reduced rays. 
oS on S _& Number of spicules of this relative 
thickness. 
ei 50 ! 
50.1— 75 . 
75.1—100 
100.1 — 125 
= 125.1—150 
Q, 
= 150.1 —175 
oO 
=: 175.1—200 
® 200.1225 
275.1 — 300 
(-yI3uay : QOOOT x SseUyxoIYL) 
375.1 — 400 
400.1 — 425 
425.1 — 450 
450.1 — 475 
Fig. 18.—Amphioxes. 
