120 ME. P. H. CAEPENTEE ON THE GENUS ACTINOMETKA. 



Fig. 3. Ventral aspect of the centre-dorsal piece. 



4 & 5. Pentagonal base of the calyx as seen from its dorsal (fig. 4) and ventral (fig. 5) sides. 

 C. Two united compound basals as seen from their ventral side. x 15. 

 7, 8, & 9, from a second specimen. 



7 & 8. Centrodorsal piece as seen from its dorsal (fig. 7) and ventral (fig. 8) sides. In fig. 8 

 three of the rays of the basal star are seen occupying the basal grooves (b. y), their proper 

 connexion with the rosette having been broken. 



9. Pentagonal base of the calyx as seen from its dorsal side after removal of the rosette and 



basal star. 

 10 & 11, from a third and abnormally developed specimen. 



10. Centrodorsal piece seen from its ventral side. 



11. Dorsal aspect of the pentagonal base of the calyx. 



Figs. 12-15 of Act. polymorpha, var. 1. 



Figs. 12 & 13. Pentagonal base of the calyx as seen from its ventral (fig. 12) and dorsal (fig. 13) 

 sides. 

 14 & 15. Centrodorsal piece as seen from its dorsal (fig. 14) and ventral (fig. 15) sides. 



Figs. 16-19 of Act. polymorpha, var. 2. 



Figs. 16 & 17. Centrodorsal piece as seen from its dorsal (fig. 16) and ventral (fig. 17) sides. 



18 & 19. Two united compound basals as seen from their ventral (fig. 18) and dorsal (fig. 19) 

 sides. 



Figs. 20-22 of Act. polymorpha, var. 3. 



Figs. 20 & 21. Centrodorsal piece as seen from its dorsal (fig. 20) and ventral (fig. 21) sides. 

 22. An isolated compound basal as seen from its ventral (a) and dorsal (b) sides. 



Figs. 23 & 24 of Act. polymorpha, var. 4. 

 Pentagonal base of the calyx as seen from its ventral (fig. 23) and dorsal (fig. 24) sides. 



Plate VII. 



In this Plate are shown the first, second, and third radials of the type of Act. polymorpha 

 (figs. 1-3) and of var. 2 (figs. 4-6). 

 The different aspects shown are designated as follows: — a. Internal or proximal face ; b. External 

 or distal face ; c. Ventral or superior face; d. Dorsal or inferior face. 



Act. polymorpha, Type. Act. polymorpha, var. 2. 



Fig. 1. First radial. Fig. 4. First radial. 



2. Second radial. 5. Second radial. 



3. Third or axillary radial. 6. Third or axillary radial. 



Plate VIII. 



All the figures are x 18. Figs. 1 & 2 of Act. polymorpha, Type. 



Figs. 1 & 2. Two successive oblique sections through the base of a decalcified calyx, viewed from their 

 dorsal side. 



Fig. 1 is the more inferior, i.e. nearer the dorsal surface. Its left-hand lower portion shows the centro- 

 dorsal piece only, with its marginal cirrhi (cir.) which receive fibrillar cords (n.c.) from the 



