; 
229 
parietes and basis meet in an elegant flexuous line. The margins of the different valves and the 
colour of the surface appear only after the Gorgonia is taken away from the surface. 
The carina is narrow at the upper extremity and much broader below; the carino- 
lateral is narrow, its breadth even diminishes from the basis to the upper end; the lateral 
is triangular, the rostrum is much elongated, as can best be seen from the figure. The 
radii are well-developed, increasing in width from the basis upwards, striated horizontally, their 
summits almost parallel to the basis; the alae seem to have oblique summits. 
The scutum-(Pl. XXIII, fig. 18, @ and c), is narrow, its basi-tergal angle not so 
much rounded off, as, according to description and figure, is the case in that of B. cymbiformts. 
The articular ridge is well-developed and extends over half the length of the valve; it is. 
distinctly reflexed. Pit for lateral depressor muscle hardly visible, cavity for adductor muscle 
somewhat more distinct. The teeth of the occludent margin are strongly developed. 
The tergum (Pl. XXIII, fig. 18, 6 and @) is broad, the outer surface beautifully and 
delicately furrowed horizontally, and not flat but flexuous. The spur is broad, its basis obtusely 
pointed. It is limited by an extremely shallow longitudinal furrow towards the scutal side of the 
valve. Crests for the depressor muscle hardly visible. 
The investigation of the animal’s body gave the following results: 
Mouth. Labrum (Pl. XXIII, fig. 19): notch triangular, wide, lateral parts nearly 
quadrangular, breadth of the sub-triangular shield greater than its height. Three teeth on each 
side of notch, and these are not pointed, but somewhat rounded at the extremity. On one side 
a tooth is wanting. 
- Palpi: oval, the upper margin not quite so strongly convex as the lower. Hairs on 
the outer surface not very numerous, forming an irregular group, some of them uniting to 
form a tuft, with hairs seen along free extremity. Hairs along upper margin rather numerous, 
those on inner surface also numerous and well-developed. 
Mandible (Pl. XXIII, fig. 20): with five teeth, and the lower angle rounded off. 
Third tooth massive, 4* and 5‘ rudimentary, with rounded extremities. Distance between 
extremities of teeth 1 and 2 hardly greater than that between the extremities of teeth 2 and 3. 
Maxilla (Pl. XXIII, fig. 21 and 21*): small notch below upper large pair of spines; 
a delicate spine situated at the bottom of the notch. Upper spines stronger than lower pair; 
between the two pairs 3 somewhat shorter spines are seen along the edge in the one maxilla, 
and 4 in the other. The latter spines diverge from the plane of the maxilla. 
Outer maxillae (Pl. XXIV, fig. 1): outer lobe with straight inner and curved outer 
margin and the extremity obtusely pointed. Numerous hairs on distal half, a single row extending 
-towards inner lobe, which is covered on its inner half with a group of feathered hairs which 
are directed inwards and downwards. 
Cirri. First pair, branches very unequal, of 7 and 14 segments. The shorter ramus 
has five of its segments distinctly protuberant. the longer ramus has about 8 such protuberant 
segments. Protuberances bear dense tufts of hairs. 
Second pair, branches slightly unequal, of 8 (indistinctly 9) and 10 segments. Hairs 
form dense tufts disposed perpendicularly on long axis of cirrus. 
IOI 
