265 
The genus is represented in the collections of the expedition of H. M. S, “Siboga”’ by 
only two samples, and each consists of only a single specimen, being one moreover, incomplete. 
1. Creusia spinulosa Leach, var. (11). 
DARWIN, CH., Monograph. The Balanidae, Verrucidae etc. 1854. p- 376, pl. XIII, fig. 6 
pl. XIV, fig. 6. 
, 
I refer to this species, although with some hesitation, a specimen of a Sessile Cirripede 
attached to and partly embedded in a piece of plate-like coral which was dredged at: 
Stat. 257. December 11, 1899. In Du-roa-strait, Kei-islands. Depth till 52 m. Bottom: coral. 
There is one specimen only, and this is incomplete as the opercular valves are wanting. 
Its orifice is small diamond-shaped, it has four compartments and distinct white radii, the 
remaining part of the shell being pale lilac-coloured. Its surface is not very distinctly marked 
with ribs, but shows numerous calcareous points which are disposed, somewhat irregularly 
however, on rows radiating from the orifice to the edge of the basis. The shell is of a conical 
shape and small, the greatest diameter of the basis being about 6 mm. 
2. Creusia spinulosa var. sumbawae n. var. Pl. XXVII, fig. 9—16. 
This variety is different from those described by Darwin; it is not embedded in a 
coral, but was found attached to a specimen of Heteropsammia (Pl. XXVII, fig. 9). Its shape 
is conical, its orifice small, elongately rhombiform; the surface of the compartments is rough 
(Pl. XXVII, fig. 10) through numerous small pointed tubercles being scattered over it. The colour 
is yellowish-brown, the radii and the basal parts of the ribs being white; the small tubercles 
on the surface are also of a white colour. The radii are rather broad at the summits, which 
are horizontal, not oblique. The surface shows the ribs round the basis much more prominent 
on one side than on the other: whilst they can hardly be seen on one side, they are distinctly 
projecting round the basal border on the other side. The basis is distinctly cup-formed, and its 
outer surface shows ribs, which radiate from the centre and whose extremities correspond 
with those of the ribs on the outer surface of the compartments. Like those of the compart- 
ments, they are much more prominent on the one side of the basis than on the other. The 
interior surface of the shell and the basis have not been investigated. 
The scutum (Pl. XXVII, fig. 11, @ and ¢) is nearly rectangular; it has the growth- 
ridges prominent and lightly crenulated, especially in the basal part of the valve; the surface 
of the part near the apex is almost perfectly smooth. The tergal margin is straight; a small 
part of the outer surface along that margin is reflexed and this reflexed part on the right 
side-scutum extends farther towards the basal margin than on the scutum of the other side. 
It terminates in the right side-scutum in a distinct tooth at the basi-tergal angle. The inner 
surface shows a very prominent articular ridge and a hardly less prominent adductor ridge, 
extending high up towards the apex. The cavity for the lateral depressor muscle is distinct, 
even rather strongly developed. 
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SBOGA-EXPEDITIE XXXI6, 34 
