92 
The IIBr series (only one present) is 4 (3 4- 4). The ossicles of the IBr series and the first 
two brachials have slight lateral extensions, and are broadly "wall-sided" as far as the base of Pj. 
The eleven arms are 90 mm. long-. The first brachial is very short, about four times 
as broad as long, only slightly wedge-shaped ; the second is irregularly quadrate, about three 
times as broad as the median length; the third and fourth form a syzygial pair which is 
remarkable for its extreme shortness, being about three times as broad as long, slightly longer 
inwardly than outwardly, the hypozygal oblong, the epizygal wedge-shaped ; the next four brachials 
are nearlj- oblong, with the distal border produced ; the following brachials are remarkably 
uniform, very short, slightly wedge-shaped, about four times as broad as the median length, in 
the middle of the arm becoming about three times as broad as long, and at the arm tip about 
as long as broad. When the arm is viewed from the side the dorsal profile of the brachials, 
though approximately straight, is seen to make a considerable angle with the axis of the arm 
so that the profile of the arm as a whole is very strongly serrate. The prominent distal edges 
of the brachials are very fineh' spinous. 
Pj is 7 mm. long with 22 segments, slender, becoming very delicate distally; the first 
segment is much broader than long, the following increasing in length and becoming about as 
lonsf as broad on the eighth and twice as longf as broad terminallv ; the second to fifth have a 
high carinate process, the crest of which is parallel with the longitudinal axis of the segments-, 
the first bears a similar, but less marked process; the sixth bears a triangular keel pro.ximally 
as high as the keel on the preceding segment but running to a point distally; the sixth and 
following segments increase in diameter from the proximal to the distal end, which makes the 
latter very prominent; the segments beyond the eighth are low triangular in section, with a 
more or less rounded dorsal ridge. P., is 9 mm. long with about 20 segments, similar to Pj 
but slightly larger with proportionately slightly longer segments, these becoming about three 
times as longf as broad distallv ; the second to fourth segments are carinate, like the second to fifth 
in Pj; the fifth has a triangular keel like the si.kth in P^; the second and following segments 
have the distal dorsal corner swollen and slightly produced. P, is 12 mm. long with 18 or 19 
segments, much larger than the preceding; it tapers more rapidly in the first four segments 
than beyond, and remains rather stiff distally ; the first segment is irregularly triangular, not 
quite twice as broad as long, the second is approximately oblong, about twice as broad as long, 
the third is slightly broader than long, the fourth is about one third again as long as broad; 
the following gradually increase in length, in the outer fourth of the pinnule becoming three 
times as long as broad or even longer; the first .segment bears a dorsal tubercle: the second- 
fourth have a narrow straight edged carinate process; the fifth bears a narrowly carinate process 
in the proximal half; on the second there is a slight projection of the dorsal distal angle which 
rapidly increases in size, becoming on the fourth and following a very prominent, though narrow, 
projection of the distal dorsal angle involving about the distal fourth of the dorsal edge, which 
is armed with fine spines. Pj is about 7 mm. long with 13 segments, and tapers more rapidly 
in the first four segments than subsequently; it resembles P3 but is proportionately smaller with 
the projection of the distal dorsal angles of the segments much less marked and the pro.ximal 
segments only very slightly carinate. P^ is 6 mm. long with 13 segments which become about 
