Invertebrate Gallery of the Indian Museum. 33 



In Tubipora the ccenenchyma consists of a mass of tubes 

 shaped like organ-pipes. 



The Alcyonacea mostly inhabit the reefs and rocks of 

 shallow waters, encrusting rocks, dead coral, etc., with 

 their funeus-like and shrub- like colonies. 



ii. ANTHOZOA ALCYONIOMORPHA PENNATULACEA. 

 [dase 4]. 



In the Pennatulacea^ which comprise the Sea-pens, 

 Sea-feathers and Sea-rods, the polyp-colony consists of a 

 more or less fleshy stem (coenosarc), one end of which is 

 buried in the mud, while at the other end are borne the 

 polyps, either on regular bilateral overlapping leaf-like 

 plates (as in Pteroeides^ Godeffroyia^ Pennatula^ Hali- 

 sceptrum, Virgularia, and Scytaliiim)^ or sessile on the 

 stem in a long row or rows {Leptoptilum), or in a bunch 

 at the end of the stalk [Umbellula), or in a head, like 

 the radiating florets of a dahlia {Veretillumy Cavernu- 

 laria). In most cases the fleshy stem is strengthened by 

 a deposit of calcareous salts in the mesoderm, and in 

 Virvnlaria the central axis of the stem forms a riafid rod. 



Examples of all the above genera (specimens preserved 

 in alcohol) are to be found in Case 4, 



The Pennatulacea are mostly adapted for life on the 

 muddy bottom of shallow seas, but Umbellula and Leptop' 

 tiluin are peculiarly deep-sea forms. 



iii. ANTHOZOA ALCYONIOMORPHA GORGONACEA. 

 [dascs 5-6]. 

 The Gorgonacea include the Sea-mats and Sea-fans, 

 and form a large group. The polyp colonies in this 

 group consist of a hard, often horny and flexible axis, 

 which is covered by ccenenchyma from which the little 

 polyps protrude. Calcareous spicules are usually deposit- 

 ed in the ccenenchyma, so that the " coral " of the Gorgon- 

 acea consists of two elements — a hard or horny central 



