756 OBSERVATIONS ON SOME AUSTRALIAN POLYCHiETA, 



Fig. 11. — Parapodium of the same. 

 Fig. 12. — Compound seta of the same. 



Plate LIV. 



Fig. 1. — Siphonostoma a (fine, lateral view of head. 



Fig. 2. — The same, ventral view of head. 



Fig. 3. — Dorsal view of head shewing eyes. 



Fig. 4. — Hooked seta. 



Fig. 5.— Papilla. 



Fig. 6.— Head of Holla australis. 



Fig. 7. — Jaws of the same. 



Plate LV. 



Fig. 1. — Parapodium of Halla australis. 



Fig. 2.— Vertical section of the mucous membrane of the oesophagus of 



Halla australis. 

 Fig. 3. — "Vertical section of wall of intestine, 

 Fig. 4. — Otocyst (?) of the same, seen in section. 

 Fig. 5.— Vertical section of the hypoderm of Syllis corruscans. 



