Erylus oiyaster Lkndenfeld. 



Figures 1-43. 



1-2:5. — Megasclcrcs; magnified 30; phot. Zeiss, planar 20 mm.: 

 1, apical view of the cladome of a dichotetraene ; 

 2-5, apical views of cladomes of dichotriaenes; 

 G, 7, pointed, straight, or slightly curved amphio-xes; 



8, pointed, angularly bent arapliiox; 



9, blunt, slightly curved amphio.x (amphistrongyle) ; 

 * 10, 11, styles; 



12-14, amphiox-derivatcs, strongly angularly bent near one end, like monaenes; 

 15, 16, amphiox-derivate with a vertically arising branch-ray, like mesomonaenes ; 

 17-19, amphio.x-derivates with two or three branch-rays, like meso- or amphiclades; 



20, side \iew of a plagiotriaene; 



21, side view of a triaene with one simple and two bifurcate cladcs; 



22, 23, side views of dichotriaenes. 



24. — View of the sponge; natural size; phot. Zeiss, anastig. 480/412 mm. 



25. — Part of a su|x>rficial, panitangential section showing a pore; magnified 200; phot. Zeiss, apochr. 8, 



compens. oc. 6. 

 26-34. — Microsclcres and groups of such from centrifuge-spicule preparations; magnified 300; phot. 



Zeiss, apochr. 4, compens. oc. 6.: 



a, (Figs. 26, 2S-33) microrhabds; 



b, (Fig. 27) large monactine o.xyaster; 



c, (Fig. 28) large diactine o.xyaster; 



d, (Figs. 26, 30) large triactine oxyasters; 



e, (Figs. 30, 32-34) large oxya.sters with four or more rays; 



f, (Figs. 29, 30) small oxyasters with numerous rays. 



35. — The umbilical face of an aspidaster; magnified 300; phot. Zeiss, apochr. 4, co*- —ns. oc. 6. 

 36, 37. — Part of the surface of the umbilical face of an aspidaster; magnified 2000" -. v. phot. Zeiss, 

 q. monochr. 1.7, q. oc. 10: 

 36, focused lower; 37, focused higher. 

 38. — A ray of a large o.xj'iister; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. oc. 10. 

 39, 40. — A small oxyaster with numerous rays; magnified 2000; u. v. phot. Zeiss, q. monochr. 1.7, q. 

 oc. 10: 

 39, focused lower; 40, focused higher. 

 41-13. — Aspidastei's; magnified 150; phot. Zeiss, apochr. 8; compens. oc. 6: 



41, rare, nearly circular aspidaster; 



42, 43, ordinary, elongate aspidasters. 



