24 



THE ANTHOZOA 



branching, the extreme basal portion of the stock generally devoid of 

 zooids and forming a stem. Zooids elongate, imbedded in coenenchyma 

 up to the stomodajal region, which is completely retractile within the 

 lower portion. Spicules mesogloeal, of various form, commonly fusiform, 

 and furnished with spines and warty projections. Genera — (a). Mono- 

 morphic forms. ylZcj/ojiiitm, Linnaeus ; Para/n/o«iK??i, M. Edw. ; Sarakka, 

 Dauielssen. (J3). Dimorphic forms. Sarcophyton, Lesson ; Lobophytum, 

 Marenzeller ; Anthomastus, Verrill ; Nannodendron, Dauielssen. Family 

 3. Nephthyidae. The zooids form upright colonies, consisting of a more 



^'^N^ i 



im- 



4. 



"^ 



■" ^.> ,^5— »i^ 



Fir.. XIII. 



1. — Clavxdaria coeruUa, Ehrb. A Clavularian colony witli a membranous stolon. 

 2.—Ammnthf(i arbnrea, Forsk. A iiu'mber of the sub-family Spongodinae. 

 3. — A grouii of zooids of the .same, mngnilied. 



4. — Umnnlin nitida, Verrill. A member of the sub-family Sii)honogorginae. 

 .■>. — A terminal branclilet of the same, majiiiitied. 



o. — Hcterojoenia elizalirlhai', Kull. A colony divided vertically to show the elongate cavities 

 of the autozooid.s, az, between the exsert portions of which are siphonozooids, jc. 



or less sterile trunk, and variously ramified branches bearing terminal 

 zooids or clusters of zooids. The tentacular region of the zooid is not 

 retractile into the gastral region, but the tentacles, when at rest, are 

 simply folded over the oral disc. The wide canals whidi run longi- 

 tudinally in the stem and larger branches are continuations of tlie 

 cavities of the principal zooids of the clusters. There are two sub- 

 families. 1. Spongodinae. The partitions between the stem canals 

 contain few or no spiculea Genera — Nephthya, Savigny. The zooid 

 lieads beset with long and large, but not jirojecting spicules. Sponijodes, 

 Lesson. The zooid heads protected by projecting tufts of long spicules. 



