PLATE XIII. 



Fig. 1. 



Fig. 2. 



Fig. 3. 



Fig. 4. 



Fig. 5. 

 Fio-. 6. 



Fio-. 7. 



Fig. 8. 



Fio. 9. 



Fig. 10. 



Fig. 11. 



Fio-. 12. 



Gellius glacialis, oxeote spicule from dermal layer ; x 180, 



Gellius calyx, oxeote spicule from dermal layer ; x 180, 



6*e^/ms sp., strongylote spicule ; x 180, 



Gellius glacialis, YSiX. nivea, oxaotti siAgvXq; x 180 



(re^^ws ^agre^Z^/er, oxeote spicule ; x 1 80, 



Gellius carduus, var. magellanica, oxeote spicule ; x 180, 



Gellius carduus, strongylote spicule ; x 180. 



(re^Zms Z«ms, stroiigylote spicule ; x 180, 



Gellius calyx, sigmata ; x 320, 



Gellius fiagellifer, sigma ; x 320. 



Esperella murrayi, sigmata ; x 330, . 



Gellius glacialis, var. nivea, sigmata ; x 320, 



Fig. 16. 



Fig. 13. Esperella murrayi, diagrammatic vertical section across one of the crack- 

 like pore-areas, showing the arrangement of the skeleton ; a, pore- 

 area ; b, dermal skeleton ; c, primary fibres ; d, secondary fibres, 



Fig. 14. Esjierella murrayi, tnchodrsigmsita ; x 260, . 



Fig. 15. Gellius glacialis, sigmnta ; x 320, . . . . . 



EsjiereUa murrayi, portion of a pore-area, seen from above, showing the 

 arrangement of the surrounding skeleton, slightly diagrammatic ; a, 

 brushes of spicules fringing the margins of the crack ; h, transverse 

 bands of fibres ; c, pores ; d, spicules of the dermal skeleton. (The 

 microsclera are not represented.) x 40, . 



Esperella murrayi, palmate anisochela from a rosette ; x 500, 



EsjJerella murrayi, stylus, ; x 180, . 



Gellius glacialis, portion of dermal layer, showing the arrangement of the 

 spicules ; x 62, ....••• 



Fig. 17. 



Fig. 18. 



Fig. 19. 



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