193 
The first brachial has the proximal and distal ed<res parallel, the outer edj^e sli<,dnly 
produced and faintly scalloped, the inner ed^es in apposition, in their distal half everted and 
scalloped; a similar len,i;;th of the inner portion of the distal ed^re is similarly everted and 
scalloped, and the inner distal anorle is rounded and produced into a thin rounded process with 
more or less scalloped border; the proximal border, and the distal border other than the 
portion described, is unmodified. 
The second br;ichi;il is about the lenj,ah of the first, slightly wedge-shaped; the distal 
edge is everted and stands out at riyht angles to the axis of the arm in the form of an 
enormous thin rounded or fan-shaped crest with a rounded or broadly scalloped edge, sometimes 
divided in the middle, which may reach 1.5 mm. in height, or from three to four times the 
greater (outer) length of the ossicle; the proximal outer corner of the .segment is slightly 
produced backwards over the distal outer corner of the first brachial, and is scalloped or 
slightly tuberculated ; the produced inner distal angles of the first brachials reach as far as 
the base of the crest. 
The third brachial (the hypozygal of the first syzygial pair) is oblong, 'very short, five 
or six times as broad as long, unmodified. 
The fourth brachial (the epizygal of the first syzygial pair) is very short, oblong, little 
if any longer than the third (the hypozygal) ; the distal 
border is everted and produced into an enormous crest 
similar to, and nearly or (juite as large as, that on the 
second brachial. 
The fifth brachial is slightly wedge-shaped, with a 
crest about half as high as that on the preceding brachial 
and more irregular. 
Fig. II. 
The si.xth has a stronsflv produced and thickened , , . , , . , 
" ' ^ Lateral view of the proximal portion of a 
distal edge which is coarsely scalloped. specimen of Stiotonutra ornaHssimus from Stat. 
" 1 • T- 1 1 11 ^ r 122. X 4- (t^ouf'esv of the U. S. National Museum). 
the seventh is slightly wedge-shaped, irom two 
to two and one half times as broad as long, with the distal edge .slightly produced in the 
direction of the axis of the arm and finely spinous. 
After the tenth or twelfth the brachials become triangular, about as long as broad, and 
after four or five more very obliquely wedge-shaped and longer than broad, and distally longer 
and less obliquely wedge-shaped. Beyond the sixth the brachials are almost smooth, with only 
slightly produced and finely spinous distal edges. 
P, is about 4.5 mm. long with about thirteen segments of which the first two are 
broader than long with rounded dorsal processes, the third is slightly longer, the fourth is 
about as long as broad, and those beyond the seventh are slightly longer than broad. P, is 
about 4 mm. long, similar to I'j , composed of twelve segments of which the outer are slightly 
longer than those of P,. The genital pinnules are about 4 mm. long, with the fourth, fifth and 
si.^ith segments enormously expanded, roofing over the gonads which are also protected ven- 
trally by strong calcareous plates of irregular shape; the seventh and following segments are 
small and slender. 
SIBOGA-EXPEDITIE XI.Il/'. 25 
