Family Muriceid.e Verrill. 



Muricea Lamouroux, Exposition Méthodique, 1821, p. 36. 



Muricea Milne Edwards and Haime, Histoire naturelle des Coralliaires, 1S57, Vol. I, p. 142. 



Muriceadce Studer, Monatsber. d. k. preuss. Akad. d. Wiss., Berlin, 1878, p. 641. 



MuriceidcR Verrill, Buil. Mus. Comp. Zool., XI, N° 1, 1883, p. 30. 



Muriceida Wright and Studer, Challenger report, Alcyonaria, 1889, p. 92. 



Mtiriceidis Hiles, Gorgonacea collected by Dr. WlLLEY, 1899, p. 197. 



Muriceida Bourne, Treatise on Zoology, Part II, Anthozoa, 1900, p. 28. 



Muriceidce Hickson, Cambridge Natural History, Vol. I, 1906, p. 355. 



Axis cylinder horny, not divided into segments; water-vascular canals not in a regular 

 series arranged around the axis; calyces of various shapes, but never with their margins turned 

 towards the branch or stem. A pseudo-operculum is almost always present consisting of spicules 

 borne on the dorsal surfaces of the tentacles; there being eight segments to the operculum, 

 each segment usually consisting of three spindles which form an acute-angled triangle with its 

 apex directed towards the centre of the mass of infolded tentacles. A well-marked collaret lies 

 below the operculum, and consists of one or more transverse rows of spindles. The spicules 

 vary exceedingly in size and pattern, but are never in the form of greatly flattened scales 

 with radiating costse produced into marginal points. The ccenenchyma usually has a bristling 

 appearance, due to the projecting points of spicules. 



This family seems to be a fairly natural one ; but it intergrades on the one hand with 

 the Primnoidae, and on the other with the Plexauridae. It differs from the former in not havinsr 

 a true operculum emplanted on the calyx margin, but instead, has a pseudo-operculum of eight 

 segments, each segment being composed of several spicules, instead of one as in the Primnoidoe. 

 There is an approach to the primnoid type of spicule in some of the scale-like plates of 

 Placogorgia ; but without radiating costse. 



The relationship of the Mtiriccidc? seems closest with the Plexauridc?, the superficial 

 resemblance being such as to deceive any one, especially as in such species as Placogorgia 

 cryptotheca which greatly resembles Plexatiroides not only in general appearance, but also in 

 form and arrangement of spicules. 



The main difference between the two families is shown by a study of a cross section of 

 the stem. In a plexaurid such a section will reveal a thick ccenenchyma enveloping the axis; 

 while around the latter is a symmetrical series of distinct round or oval openings, sections of the 

 primary water-vascular canals. In a muriceid a similar section would show a thinner ccenenchyma, 

 and no regular series of canals, these being irregular both in section and disposition. 



