AICTOITARIA. 353 



■4 by •! millim., or else longer and proportionally more slender, -with 

 more distant and simple tubercles, -4 by "08 miUim. Those (ii.) of 

 the denser axial substance are short, very boldly tuberenlate forms, 

 very irregularly modified from the fusiform types, but with the 

 tubercles somewhat scattered ; size •! 4 by "042 to '18 by -07 millim. ; 

 intermixed with these are some of the stouter and longer forms 

 which compose the outer layer. The spicules are either devoid of 

 any colour or very faintly yellow. 



Hah. Arafura Sea, off N.W. coast of Australia, 32-36 fms. ; 

 bottom — sand, mud, and shell. 



Ohs, The only differences which distinguish these specimens from 

 Klunzinger's are the pale brown instead of red colour of the corallum 

 as a whole, its unbranched condition, and the want of a decided 

 coloration of the spicules themselves. 



A specimen of this species also occurs, in an exclusively repent 

 form, upon an elongated sponge in the dry state ; it extends 120 

 millim. (5 inches) horizontally, exclusive of branches. It exactly 

 resembles the horizontal parts of the specimen just described, but 

 sends up no vertical axes, and might thus have been taken for a 

 CalKpodium had the radiate spicules assigned to this t3'pe by KoUiker 

 and Verrill been present. This resemblance of the young stage of 

 a typical Briareacean to that genus perhaps supports Kolliker's views 

 as to the genus properly finding its place among the Briareacese. 



SOLENOCAULUm. 



Solenocaulon, Gray, P. Z. S. 1862, p. 34, figs. p. 36 ; Ann. ^ Mag. iV. 



M. (3) X. p. 147 (1862). 

 ? Coelogorgia, M.-Edviards and Haime, Hist. Corall. i. p. 191 (1857). 

 Solenogorgia, Oenth, Zeitsch. wiss. Zool. xvii. p. 429 (1867). 



30. Solenocaulum tortuosum. 



Solenocaulon tortuosum, Gray, II. eo. 



A single (dry) specimen of this very remarkable form came up 

 with the tangles from a dredging of from 12 to 20 fms. off Port 

 MoUe, Queensland ; it is about 5 inches long, or rather less than 

 half the length of the type specimen. It is of a pale orange colour, 

 in which, as in its other external as well as in its microscopic cha- 

 racters, it agrees with the original type of the species. The stem 

 is solid, as is that of a spirit-specimen already in the collection, and 

 as (so far as I have been able to ascertain with safety) that of the 

 type specimen, and affords another point of agreement between this 

 genus and Solenogorgia of Genth, and adds one more reason to those 

 given by Studer (MB. Ak. BerUn, 1878, p. 669) for uniting the 

 two genera under the older name conferred by Gray, a proceeding 

 which is obviously necessary. 



Another specimen, from the Arafura Sea, fortunately preserved 

 in spirit and practically complete, although two apical portions 

 are detached, differs somewhat from the typical form. It has a 

 stem 55 millim. long, of which the lower end, to the length of about 



2a 



