Plate I. 



Fig. I. Pliobofhrits symmetriciis-^ front surface of an intact colony from the "Ingolf ' St. 55. Natural size. 



— 2. — — hind surface of the same colony. Nat. size. 



— 3. — — two ends of branches from "Ingolf St. 55. 4/j. 



— 4. Stylastcr gemviascens\ one of the type specimens of Gunner us' Madrepora virginca from the 



west coast of Norway. Nat. size. 



— 5. Stylaster gemmascens\ front surface of an openly built colony from the Trondhjem Fjord. 



Nat. size. 



— 6. Stylaster gemmascevs\ hind surface of same colony. Nat. size. 



— 7. — — front surface of the compact branch of a fertile colony ($) from the 



Trondhjem Fjord. Nat. size. 



— 8. Stylastcr roseus\ front surface of a fragment of a colony from Angmagsalik with male ampullae 



Nat. size. 

 — 9. Stylaster roscus\ hind surface of the same fragment. Nat. size. 



