10 Proceedings of the Royal Society of Victoria. 



DESCRIPTION OF PLATES. 

 Plate I. 



Fig. 1. A node of Cnjptozoon wilsoni, with the polypides 

 alive and their tentacles protruding from between the 

 grains of sand. Owing to the manner in which the 

 node is viewed the polypides are visible only around 

 the margin, though, of course, occurring all over the 

 surface, {pop.) Projecting portion of polypide. (s.g.) 

 Sand grains. (Inn.) Chitinous, tubular internodes. 



Fig. 2. Portion of coenoecium of Gryptozoon wilsoni, more 

 typical form, x 10. (iV.) Nodes. {Inn.) Internodes. 



Fig. 8. Portion of coenoecium of Gryptozoon wilsoni, larger 

 variety, x 4. {N.) Nodes. {Inn.) Internodes. 



Fig. 4. Coenoecium of Gryptozoon concrctiirn. x 4. (B.e.) 

 Basal expansion. {N.) Nodes. {Inn.) Internodes^ in 

 this case almost entirely suppressed. 



Plate II. 



Fig. 5. A tubular internode of Gryptozoon wilsoni, sepa- 

 rated by teasing, with a number of sand grains, held 

 together by the chitinous branches and the zooecia, 

 still adherent at either end. {Inn.) Internodes. {s.g.) 

 Sand grains. {cJi.) Remains of chitinous branches and 

 zooecia, cementing the sand grains together. 



Fig. 6. Lophophore of Gryptozoon concretuni seen from 

 above ; from a specimen teased up alive. (o.) Mouth. 

 (n.g.) Nerve ganglion. (ten.) Tentacles (bases only 

 represented). 



Fig. 7. Diagrammatic longitudinal section of a portion of a 

 tentacle of Gryptozoon, passing through one of the 

 longitudinal rows of columnar ciliated cells. (can.) 

 Central canal, (s. I.) Inner structureless lamella, (ep.) 

 Ordinary epithelium, (c. c.) Columnar cells, (ci.) Cilia. 



Fiof. 8. Diacrrammatic section throuoh the ffizzard of 

 Gryptozoon, showing the chitinous teeth implanted in 

 the muscular mass. The section is supposed to pass 

 through the two openings of the gizzard, and at right 

 angles to the plane of the paper in Figs. 11 and 12. 

 {c.m.h.) Sections of circular muscle band, (t.) Sections 

 of chitinous teeth. 



Fig. 9. Optical longitudinal section through the stomach of 

 Gryptozoon concretuni, passing through its two 



