60 Bulletin Vanderbilt Marine Museum, Vol. VII 



ornamented with numerous convex nodes and less frequently with 

 perforations of small, irregularly oval or elongate design in the 

 surface interstices, among the convex nodes. A thin, transparent 

 variety of this scale is shown in figure e. These latter scales are 

 less abundant, but are larger than the above described rosettes. 

 The sphaeroidal bodies are moderately abundant, less frequently 

 ovoidal, in each instance with the external surface continuously 

 beset with asperities. 



Two types of long needle-like spicules are moderately abundant 

 in the cortex of the rachis : three varieties of long, bowed needles, 

 one smooth, distally tapered, in both directions ; a second variety 

 bowed and distally terminating at each end in a cluster of eight 

 to ten bristly spines ; a third kind, bowed, shorter than the pre- 

 ceding variety, wider in ratio to length, with the two flat lateral 

 surfaces distinctly transversely striate, like a file. There are also 

 needle spicules with one end distinctly flexed into a wide curve, 

 the more elongate of such spicules being tapered at both ends ; the 

 shorter forms being thicker with the distal ends dilate and spinose. 

 A rather rare type of spicule is the spiral, variously of a one and 

 a half to two or more whorls, with both distal ends terminating 

 in a cluster of long divergent spines. Single and double star- 

 shaped spicules are also present in varying growth stages. 



The axis is a deep ivory color, four-sided in transverse section, 

 nearly square, with the angles blunt and the sides moderately 

 concave. (Plate 12, figure c.) It tapers proximally, beginning 

 near the base of the bulbous stalk and continues in the rachis 

 where it is thick for the proximal half, 2.5 millimeters wide, more 

 slender distad, the tip of the axis extending quite to the apex of 

 the trunk. 



It is a pleasure to dedicate this species to the collector and 

 Commandant of the "Ara" World Cruise, Mr. William K. Vander- 

 bilt. 



