338 THE VOYAGE OF H.M.S. CHALLENGED. 



company of our countrymen. He doubts if the English naturalists obtained any other 

 specimen of this sponge [Dendrospongia) , though he told them of his one, and where 

 and how acquired." In a note Murie made the following addition : — " Since reading this 

 communication, Sir Wyville Thomson's return has enabled me to show him the accom- 

 panying plates ; the species he does not recognise as being among their collections, 

 although it is possible a less perfect specimen or fragmentary portions may be found 

 among the stores of material as yet imperfectly worked out." 



According to Murie's description and figures, " The general surface exhibits several 

 broad but very shallow impressions or concavities which traverse the stem obliquely. 

 The distinguishing feature of the branches is a series of tufts or rosettes, so continuous 

 and interwoven as in the main to present a whorl running successively round from base 

 to apex, composed of a bunch of long parallel placed spicules, which issue from the axis 

 of the branch at an oblique angle, and slightly spread out at their free ends. The spiral 

 hollow between the frill shows a delicate gossamer lacework composed of minute spicules, 

 forming a rectangular chequer." 



The principal fibrous bands of the network of beams, which is composed of fused 

 hexradiate spicules, run, according to Murie's representation, in a longitudinal direction 

 in the axial part of the branches, but bend laterally in a bow-shaped curve towards the 

 exterior, and terminate freely in the more radially directed obliquely projecting fibres of 

 the spiral frill. All were covered with short mucronate spines. 



Among the spicules which lie isolated Murie described (l) long acerate, fusiform, 

 inequilateral sj)icules of two sizes, large and small, both covered with spines, all sloping in 

 the same direction ; (2) two forms of scopuline spicules, the larger with a straight shaft, 

 and with microspined and indistinctly capitate terminal rays, from two to four in number, 

 the smaller with two to four rays opposite to one another, and expanded laterally like 

 petals. 



In regard to the position of these scopuline spicules, Murie' records Carter's conjecture 

 — illustrated by a woodcut — that they may have lain parallel to the surface in the dermal 

 layer, and may have been crossed in such a way that square meshes were formed. He 

 found (3) two forms of rosettes, of which the smaller bore six straight, smooth rays rising 

 at right angles from the centre, and each terminating in a little discoid swelling bearing 

 four to eight rays spreading in what Carter terms Vijieur-dc-Us. Each ray terminates in a 

 swelling which is expanded into a circular convex head, bordered by four opposite and 

 recurved spines. The larger rosettes are very rare, and the globular still more so. Each 

 of the six short, stout rays terminates in a quadrangular swelling, which bears several long, 

 straight rays, ending in a quadrangular, or, more frequently, pentangular cap or head, 

 with free convex surface, but jjrovided with recurved spines at the angles of the opposite 

 surface. He also notes (4) single hexradiate dermal spicules, which form by the over- 



' Loc. cit, p. 227. 



