PLATE XXX. 



Aseidia challengeri, n. sp. 



Fig. 1. Aseidia challengeri, a large specimen, seen from the right side ; natural size. 



Fig. 2. A much younger specimen, from the right side ; natural size. 



Fig. 3. Part of a section through the test of Aseidia challengeri, showing vessels (r.) 



1 "ladder cells (hi.), &c. ; magnified (Hartn., obj. 4). 

 Fig. 4. Part of the branchial sac, seen from the inside ; magnified (Hartn., obj. 4). 

 Fig. 5. Part of the dorsal lamina of Aseidia challengeri, seen from the left side; magnified 



(Hartn., obj. 4). 

 Fig. 6. Another part of the same dorsal lamina, with a crenated and toothed edge, seen 



from the left side ; magnified (Hartn., obj. 4). 

 Fig. 7. Another part of the same dorsal lamina, near the base, where it is wide and has 



strongly marked ribs ; seen from the right side ; magnified (Hartn., obj. 4). 

 Fig. 8. The dorsal part of the anterior end of the branchial sac, showing the dorsal 



tubercle (d.t.), the prjebranchial zone, with muscle bands («i.&.) showing 



through, and two of the large tentacles (tn.) ; magnified (Hartn., obj. 5). 



