128 



REPORT OX THE ALCYONARIA. 



,, 1 , , „ uave a basal diameter of 



the larger branches one of 2-5 mm., the terminal bran ■.,-,. • i i -.i 



, . J • 1 p .IS thm, but provided with a 



I ;) mm., and an apical one of 2-2 mm. The ccenencl- n , • « r i 



1 r. , -Till., ^, J-i'e found chieriy on one surface, and 



layer of large spindle-shaped spicules. The po' , , •, , 



,1 ■ p ,^ -, „ , "he colon V, while the other portions ui 



on the margins of the stem and of the twio-s ^, :. , , , • 



,1 r 11-,, ° i<i- i he distance between the polyps is 



the surface are covered onlv with the coenencl- , n ,. , , , t j r 



p „ , , , . ,^ ," , • , , , .i/tened ends of the branches there are two 



from 1 to 1-0 mm. On the thickened an' ,-, , , • , , 



^ •, , mi , erect, wart-like body, with a broad base ot a 



opposite polyps. The })olyps present ' , ^ , ■ 



T , f. , - ,",.,. 6 mm., they are closed by an imperfect operculum, 



diameter of 1-.5 mm., and a heiirhf , t , , , , 



rpi . , ,1 T ■jie by the eye. In the coenenchyma they are somewhat 



1 he spicules are mostly d'^' , •' ■; . ... 



n .. 1 -1, -^M margins are furnished with dentations, which can intercalate 

 tlattened spindle« ... 

 ..vi |i ^. o^e neighbouring spicule. Sometimes, especially towards the base of the 



polyps, they exjjand into longish discs truncated on both sides, or running out into short 



prominences. Their .surfaces are covered with rough wart-like protuberances. The 



longest spicules have a length of 3 mm., with a diameter of 0'2 mm. ; others measure 



l"3-0"5 ; 0"9-0"3 mm. On the polyps the spicules are discoid, arranged in the form of 



a ring, sometimes triangular, sometimes rhomboidal ; towards the margin of the calyx 



they are scale-like, and the protuberances often take the form of comb-like teeth. Theii' 



thickness differs very much ; their length by breadth is 0"9-0'3 ; 0'4-0'3 mm. 



The operculum is formed of smooth, scaly and dentate spicules, wdiich are found in 

 the basal portions of each tentacle ; these are at once distinguished by their violet colour, 

 which contrasts with the white spicules of the body. Sometimes these are spear-shaped ; 

 sometimes they remind one of the Stachelplatten of Paramuricea. Their length by 

 breadth, i.e., the greatest diameter, is 0-54-0-41 ; 0-4-0-2 ; 0-26-0-07 ; 0-2-0-05 ; 

 0'33-0'16 mm. An incomplete ring of curved blunt spindles forms the colleret. The 

 axis is horny, rigid, and of a brownish-yellow colour ; it is very feebly flexible. The 

 colour of the coenenchyma and of the polyps is white, but the oral region is of a dark 

 violet. From Acis orientalis, Ridley, to which this species is nearly related, it may be 

 distinguished by the form of the spicules and by the compressed stem. 



Habitat. — Station 232, the Hyalonema-gvm\n(\, Japan ; depth, 345 fathoms ; bottom, 

 green mud. 



Genus 12. Muricella, Verrill. 



Muricella, Verrill, Trans. Connect. Acad., vol. i. p. 4.50, 1869. 



Verrill {loc. cit.) subdivides the genus Muricea, as emended l)y Kolliker, into three 

 divisions. One, Muricella, comprises the East Indian species ; the species of the other 

 two, Muricea and Eumuricea, being chiefly limited to the Atlantic Ocean and to 

 the West American coasts. But Minicella, at least, differs so much from the others 

 that we feel justified in keeping it gencrically apart ; a conclusion adopted by Ridley. 



