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with light rose and red. Radii extremely narrow with oblique summits, alae narrow also and 
with oblique summits. Scutum plainly striated longitudinally; tergum with the spur broad, 
without a longitudinal furrow. 
This species in several respects resembles B. amaryllis, and belongs no doubt to the 
same division of the genus. It is represented by two specimens. 
The general shape of the shell (Pl. XVI, fig. 5) is conical, with, the basal part, in the 
larger specimen especially, rather swollen, and a relatively small and deeply toothed orifice. The 
shell is slightly compressed laterally, in consequence of its being attached to a narrow and 
rounded surface. The basis is hollowed out, with the concavity directed towards the object 
(sponge?) to which it is attached; this basis is calcareous; I could not make out if it has pores. 
The compartments and radii have no pores. The radii are narrow, and have the summits very 
oblique; the alae are only slightly broader, they have the upper margins rounded and oblique. 
The colour of the shell and radii is pale red, with darker and lighter longitudinal stripes, crossed 
by a few horizontal and lighter-coloured bands. The alae are much lighter, almost of a white 
colour. The larger specimen measures 11 mm. (greatest breadth at the basis), and has a height 
of 9.5 mm. In the smaller specimen these measurements are 7 and 5.5 mm. respectively. 
Scutum and tergum in general appearance resembling very much the same parts in BZ. 
amaryliis. The longitudinal striae on the scutum (Pl. XVI, fig. 6, a and c) of the present species 
are, however, still more distinct, hence the whole surface is divided into little squares in a more 
prominent way. The inner surface of the scutum is coloured purplish-red, and is distinctly 
furrowed longitudinally, especially in the basal part. The adductor ridge can be made out only 
in the superior half of the valve, the articular ridge is narrow, and about half as long as 
the tergal margin. 
The tergum (Pl. XVI, fig. 6, 6 and @) has the scutal margin hollowed out, the apex 
beaked. There is no longitudinal furrow. The spur is short, and cut off in an oblique direction. 
Its length is a trifle longer than its distance from the basi-scutal angle. Crests for the depressor 
muscles few and not very prominent. 
With regard to the structure of the animal’s body, the following may be said: 
Mouth. Labrum (Pl. XVI, fig. 7) with a rather deep notch, and three teeth situated 
close together on each side of notch. The two margins of the labrum on each side of the 
notch together make an angle; therefore the whole shape of the shield-like portion, is more 
quadrate than triangular. The teeth are triangular, pointed at the extremity. 
Palpi with the basal margin strongly arched, hence the whole shape is swollen as in 
B. amaryllis. Numerous longer hairs are situated close together on a triangular portion of the 
outer surface at the free upper corner. Hairs along upper margin numerous; those of the inner surface 
are arranged above and along a distinct ridge, which runs parallel to the upper margin. When the 
palpi are at rest, a row of these hairs disposed along the ridge, falls over the edge of the labrum. 
Mandible (PI. XVI, fig. 8). Distance between extremities of teeth 1 and 2 about 
the same as that between 2 and 3. The latter teeth double. The 34 somewhat thicker, the 
4th small, 5% and inferior angle form together a blunt projection. The part of the mandible 
5 
behind the 3" tooth only slightly developed. 
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