HYPDRGON SKEATI. 735 



PLATE U. 



Fig. 1. — A piece of a colony of Ilypurgon Skeati, slightly larger Mkiii 

 natural size. 



EiG. 2. — A portion of the surface of a colony seen under a binocular micro- 

 scope. X 75. 



Tig. 3. — Calcareous spicules from thetestof Hypurgon Skeati. « and 6 

 from one colony ; c, e, audy from a second. /, a cluster of spicules. 



Fig. 4. — A vertical section through a part of a colony of Ilypurgon 

 Skeati, showing the branchial sac and parts of the abdominal cavity of one 

 zooid (slightly reconstructed from neighbouring sections), x SO. 



Fig. 5. — Vertical section of an abdominal cavity. 



I'lG. 6. — Diagrammatic reconstruction of a slice of a colony of Ilypurgon 

 Skeati, showing one zooid from the left side and one from the dorsal surface. 

 Drawn as though it were transparent. 



I'LATE 35. 



Fig. 7. — Section of a renal organ of Ilypurgon Skeati which lias been 

 functioning long enough to form the considerable accumulation of concre- 

 tions K. 



F^iG. 8. — Portion of the test of H. Skeati containing renal vesicles, more 

 highly magnified. 



I^IG. 9. — Section of an abdominal cavity of zooid of II. Skeati, to show 

 reproductive organs. 



F'iG. 10. — Sectionof alarge ovum of II. Skeati in arecess of the abdominal 

 cavity. 



l^iG. 11. — Section of a tailed larva of 11. Skeati developing in a closed 

 cavity in the test. 



