EXPLANATION OP PLATE XIII. 



Saccoeali/j' p>iliiuciil(d(i. F. E. Sell. 



Fig. 1. A specimen with tlie upper end of the peiliincle; above, a part of 

 the body-wall is cut away. Nat. size. 



Fig. 2. Lower end of the peduncle. Nat. size. 



Fig. :3. Arrangement of the spicules in a transverse section of the up])er 

 part of the lateral body-wall, vertical to the surface. % :5() (combined figure). 

 Fig. 4. Parenchymal discohexaster with spirally twisted branch-rays. 

 X 300. 



Fig. 5. Terminal disc of a parenchymal discohexaster, viewed obli(juely 

 from within. x 1000. 



Fig. 6. Marginal view of a terminal disc of a parenchymal discohexaster. 

 X 1000. 



Fig. 7. Parenchymal plumicom. x 1200. 



Fig. 8. Lateral view of a ray of a parenchymal plumicom. x 2000. 

 Fig. 9. Parenchymal discohexaster, most of the l)ranch-rays of which 

 have been broken off near the base. x .500. 



Fig. 10. A group of spii-ally twisted branch-i-ays of a parenchymal dis- 

 cohexaster belonging to one main-ray, seen from Avithout. x .500. 



Fig. 11. Fragment of the supporting skeleton of the peduncle containing 

 parts of four diactine rhabds, connected by numerous synapticula. x 'iOO. 



