208 



ACTINOZOA, 



presenting this combination of characters has been 

 observed. The family Merulinidce has, lastly, 

 been constituted for the reception of an equally 

 aberrant Astrseoid genus, Merulina, which clearly 

 points in the direction of the Fungidce, resembling 

 these corals in the perforate condition of its eoral- 

 lum, though, as in the true Astrceidce, no synap- 

 ticulae occur. 



3. Order 2: Alcyonaria. — The A Icyonaria, 

 with the exception of one genus, Haimeia, which 

 may, however, yet prove to be an immature form, 

 are composite in structure; their polypes being 

 mutually connected by a coenosarc, through which 

 permeate prolongations of the somatic cavity of 

 each, forming a sort of canal system, whose several 

 parts freely communicate and are, therefore, rea- 

 dily distensible. 



Throughout the whole order the polypes exhibit 

 a very close agreement in structure, howsoever 

 much the coenosarc may vary. Each, when ex- 

 panded, displays a cylindrical, or somewhat octa- 

 gonal, tube, with delicate transparent walls, and 

 eight pinnate tentacula, whose form offers slight 

 though characteristic variations among the several 

 genera of the group. In some the polypes are 

 retractile into excavations which occur in the sub- 

 stance of the coenosarc, while in others such 

 excavations seem to be wanting. 



Alcyonium, the typical genus, presents, when 

 first dredged up, a sufficiently repulsive aspect, 

 suggestive of the vulgar names, " Cow's paps " and 

 " Dead-man's hand," sometimes conferred on it. 

 But, when placed in sea-water, the lobate fleshy 

 mass, distending its aquiferous system, is gradu- 







