ALCroIfAEIA. 359 



P MSlitSe ochrac^e, Be Blainville, Man. Actinol. p. 604, pi. Ixxxvi. 



flg. 3. 

 ? Mopaella retifera, Studer, MB. Ah. Berlin, 1878, p. 666. 



Lamarck's species seems not to have been clearly identified by 

 modern writers, with, perhaps, the exception of Verrill (BuU. Mus. 

 Comp. Zool. Camb. i. p. 38) ; I have, however, little doubt of its 

 identity with a form which occurs somewhat abundantly in this 

 collection from Port Molle, Queensland, &c. I have thought it well 

 to describe this form fuUy, in order to clear up the uncertainty which 

 has hitherto prevailed as to the correc-t name of the species. 



It branches strictly in one plane and has elongated meshes ; the 

 stem and main branches are slight and break up almost immediately 

 into a reticulum of undulating thin branchlets, which almost all 

 anastomose ; the terminal branchlets are only about 1 millim. in 

 diameter. The internodes are long ; the joints are small, short, and 

 squarish. The cortex is rough, rather dull scarlet ; the zooid- 

 verrucae of the same colour ; the expanded zooids, scarlet in one 

 specimen, yellow in another, are equal and small, but distinctly pro- 

 minent, abundant over the front and sides of the branches. Axis 

 of joints firm, bright red, that of basal internodes longitudinal]}- 

 channelled, deep red ; of distal -internodes faintly striated, but ot 

 the same tint, and penetrated by the longitudinal canals. 



Spicules of general cortex : — (i.) Pusiform, sharply pointed at both 

 ends, as a rule, and 'icovered with irregularly scattered taberoles, 

 which are large and blunt at the middle of the spicule, minute 

 at the ends ; dimensions -IS by '035 millim. (ii.) " Blattkeuleh," 

 large, either with long cylindrical shaft, strongly tuberculate, with 

 large compound tubercles and two " leaves " which are broad, 

 rounded, the edges divided into blunt teeth, or with the shaft more 

 or less aborted ; dimensions of spicule "21 by ■10f5 millim., length of 

 cylindrical shaft alone about •! miUim. Spicules of verrucse : — (iii.) 

 Longitudinal, curved, fusiform, tapering gracefully to sharp points, 

 with rather few tubercles, prominent and sh^rp at middle, disap- 

 pearing towards ends ; dimensions '24 by "035 miUim. (iv.) Hori- 

 zontal, very regularly fusiform, curved, pointed rather bluntly, 

 covered with very closely set, low, blunt tubercles ; dimensions '28 

 by "041 miUim. 



Hah. Port Curtis, 5-7 fms; ; Port Molle, 12-20 fms. ; Thursday 

 Island and Prince of Wales Channel, Torres Straits, 4-7 fms. Also, 

 perhaps. Dirk Hartog Island, W. Australia, and N.W. Australia 

 (Studer). 



This is a delicate and graceful species ; it is represented in this 

 collection by two nearly perfect specimens and 4 number of fragments 

 in the dry state, and by a specimen and fragments in spirit. The 

 largest specimen measures 193 millim. (nearly 8 inches) in height, 

 by ] 46 millim. (6 inches) in maximum breadth ; the thickness of 

 the base is — joints 6 millim., internodes 4 millim. Lamarck's and 

 Lamouroux's descriptions suit the species very well, and the remark 

 of the latter to the effect that it is " pen rameuse ; se divisant subite- 

 ment en ramuscules tres-menus, filiformes, verruqueux, anastomoses," 



