484 ME. S. O. RIDLEY ON THE GENUS DIEEHOPALUM. 



Main skeleton. — Spieulo-fibres containing a large proportion of 

 pseudo-keratose ; the primary fibres at right angles to surface, 

 containing a single row of large, smooth acuate spicules (1), sur- 

 rounded irregularly by two or three rows of shorter acuates 

 (2), slightly spined basally, whose points project to the sides ; a 

 distinct margin of ceratinous material lies outside most of the 

 spicules. The secondary fibres are numerous, irregular, formed 

 of pseudo-ceratinous material, surrounding and showing distinct 

 margins outside the dumbbell spicules (3), which occur, one or 

 two together, in each fibre ; secondary fibres about one spicule in 

 length. Fine spinulate or supra-basally spinulate spicules (4) 

 (probably young forms) scattered over primary fibres. 



Dermal skeleton indefinite ; consists of a reticulation of the 

 dumbbell spicule, with the spinulates (4) scattered through it, 

 perforated at intervals by the terminal long acuates (1) of the 

 primary fibres. 



Pseudo-ceratinous material dense, pale amber-yellow. 

 Sarcode very slightly granular, of almost the same colour. 

 Skeleton- spicules. — (1) Strong, smooth, slightly curved acuate, 

 tapering to rounded base from a point at about 3 diameters from 

 it and to sharp point from same place ; size *5 by "025. (2) Smaller 

 acuate, slightly curved, slightly constricted immediately above 

 and very slightly microspined upon the base, and tapering to sharp 

 point from just above the constriction ; size -2724 by •0174. 

 (3) Dumbbell spicules ; shaft decidedly curved, and generally 

 very sparsely microspined ; ends well spined, separated from 

 shaft by slight constriction ; of about same diameter as middle of 

 shaft ; size -177 by -0158 millim. 



Flesh-spicules. — (4) Long, straight, spinulate spicules, or with 

 head just above base : various in size, viz. "19 by -0021 to "36 by 

 •00475 millim. Probably young forms of skeleton-spicules. (5) 

 Fine, decidedly tricurvate acuate, bow-shaped, tapering to fine 

 points from middle, smooth ; size '06334 by '0021. (6) Equi- 

 anchorates, bipalmate, navicular; shaft almost straight; length 

 •019 millim. 



Hah. Bay of Islands, north-eastern extremity of New Zealand 

 (Antarctic Expedition). Depth ? 



Examined in spirit and mounted in balsam from spirit. 

 Ohs. One chief mass, 48 millim. long, with about eight branches 

 given off at sharp angles from the single stem, and three or four 

 fragments of similar character, all more or less growing over the 



