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spine-like hairs all over the surface. All the segments of these cirri bear two pairs of very 
long spines on their inner face (Pl. XXVI, fig. 14). Between the spines. of the lower pair a 
few very short hairs are disposed, and between those of the distal pair of spines a few 
somewhat longer hairs. The hairs on the dorsal surface near the extremity of each segment 
are relatively short. 
Penis (Pl. XXVI, fig. 15) in all the three specimens examined extremely short, its 
free extremity not extending to the end of the pedicel of the sixth cirrus (Pl. XXVI, fig. 16). 
It is broad at the basis and much narrower at the extremity; this narrower part seems to be 
somewhat longer in the specimens from Stations 59 and 105 than in that from Station 25 Le 
The penis is finely-ringed and bears only a few hairs. A tuft of hairs is seen round the tip. No 
projecting point was observed at its dorsal basis. 
The specimens of this interesting species were collected at the following stations: 
Stat. 59. April 26,1899. Lat. 10°22'.7S., Long. 123°16'.5 E. Western entrance Samau-strait. 
Depth 390 m. Bottom: coarse coral-sand with small stones. One specimen, which 
was separated from its bottom. 
Stat. 105. July 4, 1899. Lat. 6°8'N., Long. 121° 19’ E. Depth 275 m. Bottom: coral (a very 
short haul, dredge almost immediately caught in the bottom). Two beautiful white 
specimens attached to the surface of a piece of shell. 
Stat. 251. December 8, 1899. Lat. 5°28'.4S., Long. 132°0'.2 E. Depth 204 m. Bottom: hard 
coral-sand. Trawl brought up pieces of grey clay and manganese nodules, the 
interior of which consisted of dry clay. Two specimens, one of which was broken 
and loose, the other being attached to a piece of brown stone. 
General Remarks. As I have pointed out already, the resemblance of the different 
specimens: of this species collected by H. M. S. “Siboga” is not complete. There can be no 
doubt, however, that they belong together and that they represent a species different from 
those already described by Pispry and myself. 
2. Hexelasma arafurae n. sp. Pl. XXV, fig. 12—16. 6 
Alae broadly-triangular with their summits oblique. Shell with very wide orifice, dirty 
white, without epidermis, with obscure longitudinal stripes. Inner side of scutum#and tergum 
orange-coloured. Scutum indistinctly folded longitudinally, with the articular ridge slightly pro- 
minent and a deep pit for the adductor muscle; tergum beaked, with prominent articular ridge 
and the extremity of the spur broadly rounded. 
Shell (Pl. XXV, fig. 12) dirty white, compartments rather thick, massive, standing nearly 
vertical, hence orifice very large, diamond-shaped, somewhat narrower towards the carinal 
end. Outer surface of shell with horizontal and not very distinct lines of growth, slightly more 
distinct on the surface of the rostrum. No radii present. Alae of the carina, the carino-lateral 
and lateral compartments broad, triangular, with strongly marked lines of growth and the upper 
margin irregular, partly broken off, giving the orifice a toothed appearance. The rostrum when 
seen from the inner side has the sheath developed only in the middle part — whether the 
lateral parts represent rostral-lateral compartments cannot be made out. Parietes not porose, 
nor furnished with ribs at the inner side. Basis not distinct, membranous. 
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