PLATE XXIX. 



Figs. 1—9. PachycJilama ohlonga, Herdman. 

 Fig. 10. Pachychlcena gigantea, Herdman. 



Fig. 1. Pachychlcena oblonga, from the right side ; natural size. 



Fig. 2. The same, from the ventral edge ; natural size. 



Fig. 3. A small portion of a section through the peripheral layer of test, showing the 



terminal knobs of the blood-vessels, the pigment cells, &c. ; magnified (Hartn., 



obj. 4). 

 Fig. 4. Part of the branchial sac of Pachychlcena oblonga, seen from the interior; magnified 



(Hartn., obj. 4). 

 Fig. 5. A small portion of the last figure ; more enlarged (Hartn., obj. 5). 

 Fig. 6. A small portion of the same branchial sac, showing a papilla edge-ways, an internal 



longitudinal vessel, a connecting duct, and a transverse vessel ; much magnified 



(Hartn., obj. 5). 

 big. 7. A part of the dorsal lamina; magnified (Hartn., obj. 4). 

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



showing the dorsal tubercle, the peripharyngeal band, and the bases of the 



tentacles ; magnified (Hartn., obj. 4). 

 Fig. 9. Part of the tentacular circlet of Pachychlcena oblonga ; magnified (Hartn., obj. 4). 

 Fig. 10. Terminal twigs of the blood-vessels in the test of Pachychlcena gigantea, show- 

 ing crystals attached to their outer walls (Hartn., obj. 7). 



