148 



THREE CRUISES OF THE " BLAKE. 



motion gradually with their development, and finally when adult 

 remain fixed, although they certainly move freely about when 

 young, like other shallow- water actiniae. 



Epizoanthus belongs to a group of actiniae usually forming 

 irregularly shaped incrusting masses and incapable of locomo- 

 tion. The polyps have a thick leathery column of a bluish or 

 grayish-brown color. Two species are quite common along the 

 east coast of the United States, in depths varying from 75 to 

 600 fathoms. (See Fig. 235.) 



CORALS. 



A series of fine specimens of Caryophyllia communis (Fig. 

 462) well shows their mode of growth. The young is erect, 

 with a thin peduncle attached to a small pebble or shell ; as it 



Fig. 462. 



Caryophyllia communis. 



Fig. 462 a. 

 (Pourtales.) 



grows in height, the support not being sufficient, it falls over 

 on its broadest side, and, growing upward to keep the calycle 

 above the mud, the curved base is produced. (Fig. 462 a.) 

 Stenocyathus vermiformis is a very elongate coral resembling 



an annelid tube. Specimens fre- 

 quently occur having a living and 

 growing polyp at either end. (Fig. 

 463.) These specimens are gener- 

 Fig. 463. Stenocyathus vermifor- ally somewhat curved, as if they had 

 mis. i. (Pourtai&s.) keen lying in the mud with both 



ends turned up and projecting. 



1 The account of the corals here given is taken from the various reports of 

 Pourtales on the "Blake " collections. 



