924 ADDENDA TO THE AUSTRALIAN HYDROMEDUSjE. 



(tt) Ordinary flat Epithel-cells. 

 (/;) K erven bre. 



(c) Nettle cells. 



(d) Bipolar Ganglia cell. 



(e) Irregular Ganglia cell of the nettle-wart. 



(/) Subepithelial cell producing nettle capsules. 

 {<j) Nerve tibrills radiating out from the fibre to the different 

 parts of the nettle wart. 

 Fig. 13.— Margelis trinema, R. v. L. A., Oc. III. 

 Fig. 14. — Octorhopalon fertilis, R. v. L. A., Oc. 111., 

 Fig. 15. — Octorhopalon fertilis, R. v. L. The Medusa seen from below. 



AA., Oc. II. 

 Fig. 16. — Eucope hyalina, R. v. L. A., Oc. III. 

 Fig. 17. — Eucope hyalina, A. v. L. Longitudinal section through the 



stomach and the commencement of a Radial Canal, osmic acid, 



alum-carmin. F.. Oc. II. 

 Fig. 18. — Eucope hyalina, R. v. L. An acustice vesicle with three Otolithes. 



A fresh compressed specimen. DD., Oc. II. 

 Fig. 19. — Obelia Australia, R. v. L. AA.,Oc. II. A Medusa with reverted 



Exumbrella. 

 Fig. '20. — Obelia Australia, R. v. L. The mouth seen from below. AA., Oc. 



II. 

 Fig. 21. — Obelia Australis, R. v. L. Longitudinal section through a growing 



male Sexual Organ, osmic acid, picra carmin. DD., Oc. I. 



(a) Proximal part of Hadial Canal. 



(b) Granulose part of the Umbrella Gallert just below the 



Sexual Organ. 

 (r) Ordinary Entoderm on the upper side of the Sexual cavity. 

 (</) Distal part of the Radial Canal, 

 (e) Mass of small, indistinct cells, with Protoplasme which 



does not refract the light very strongly. 

 ^/) Minute Canal leading from the cavity into this mass of cells. 

 {(j) Larger and well separated cells, filled with highly refracting 



Protoplasme near the outer surface. 

 (h) Ectodermal Epithel. 

 rig. 22. — Obelia Australis, R. v. L. Base of one of the Tentacles. Afresh 

 specimen compressed. C. , Oc. I. 



(a) Plug-shaped transparent mass inserted into the margin of 



the Umbrella. 

 (h) Proximal wall of the Ring canal. 



(c) Hing canal. 



(d) Distal wall of the Ring canal. 



(e) The rudimentary rest of the Velum. 



(/) Large Ectodermal cell of the tentacle-bulb. 

 (g) First Entodermal cell of the Axis of the Tentacle. 

 (h) Conic extension of the cavity of the Ring canal into the 

 Tentacle. 



