535 " THETIS " SCIENTIFIC RESULTS. 



five radial primary plates and ten radial shields are conspicuous. 

 Radial shields much larger than central dorsal plate, decidedly- 

 longer than wide, broadly in contact, only the proximal 

 ends being sliglitly separated by one or two small scales; 

 there is a single interradial marginal plate, wider than 

 long, between each two pairs of radial shields. Upper ai'm- 

 plates broadly triangular, much wider than long, with 

 convex distal margin and rounded outer corners ; somewhat 

 swollen ; all, or all but first two or three, separated by side arm- 

 plates. Interbracliial spaces below covered with a rough pave- 

 ment of very large, coarse granules, in marked contrast to the 

 plates of the upper side. Genital slits wholly wanting. Oral 

 shields wider than long, with straight distal and lateral margins, 

 the latter parallel to each other ; proximal margin with an angle 

 inwai'ds. Adoral plates rather large, somewhat swollen, about as 

 wide as long. Oral plates indistinct. Oral papillae closely 

 fused, apparently two or three on each side and a very large one 

 at apex of jaw. Underarm-plates swollen, about as wide as long, 

 pentagonal with a sharp proximal angle and rounded distal angles, 

 all except first two separated by side arm-plates ; first under arm- 

 plate decidedly longer than wide, its outer end wider than inner. 

 Side arm-plates large, swollen, meeting above and below, except 

 at very base of arm ; each plate carries two minute, stout, pointed, 

 spines, about half as long as joint, or more, the lower the longer. 

 Tentacle-scales, none, except a very minute one on inner distal 

 side of first pore ; pores very large. Colour (in alcohol) pale- 

 yellowish or whitish. 



117 specimens from Station 13. Off Cape Three Points, 41-50' 

 fathoms ; sticky mud and shell. 



88 specimens from Station 22. Newcastle Bight, 26-40' 

 fathoms ; grey sand to mud and shell. 



9 specimens from Station 35. Off Port Hacking, 22-38 

 fathoms ; sandy. 



10 specimens from Station 38. Off Jibbon, 46-55 fathoms;: 

 sand to mud 



95 specimens from Station 57. Off Wata Mooli, 54-59 fathoms; 

 all mud. 



This little species, which makes up three-quarters of the 

 collection of Ophiurans, appears to be very common on suitable 

 bottom off the coast of New South Wales. Owing to its small 

 size, it is easily overlooked, and it is not strange that it has 

 escaped observation and description hitherto. There is no other 

 species with wlrch it can be confused, the peculiar covering of 

 the ventral interbrachial spaces, combining with the absence off 

 tentacle-scales to separate it sharply from all other members of, 

 the genus, or even of the family. 



