eet 
ORINOIDEA—CLARK. 15 
so that the last eight are scarcely longer than broad. After about the twelfth the 
median portion of the distal dorsal border becomes very slightly prominent. In dorsal 
view the middle third of the distal edge is seen to be slightly bowed outward and serrate. 
Later this becomes slightly elevated and more strongly serrate, appearing in lateral view 
as a slight terminal spine directed obliquely forward. Distally this projection slowly 
narrows, on about the tenth segment from the end the dorsal surface of the segments 
becoming broadly and roundedly subcarinate; the median elevation gradually becoming 
still narrower and more easily evident, and the last two segments before the penultimate 
are distinctly carinate dorsally. The opposing spine is a longitudinally elongate tubercle 
occupying the distal half of the penultimate segment. The terminal claw is somewhat 
longer than the penultimate segment, moderately stout and evenly curved. In the outer 
half the cirri taper very slowly and gradually to a slender tip. 
The proximal pinnules may be described as follows (large specimen from Station 
12) :— 
P, is 20 mm. long with 50 segments. The first 4 or 5 segments are about twice 
as broad as long, and the remainder are all broader than long. The third and following 
segments have a prominent carinate crest on the side toward the arm tips. On the 
third the crest is broad and gently convex, on the fourth and fifth the process is roundedly 
pointed, and on the segments following the crest long and high, rising to a height of half 
the width of the segment or more, with the outer edge straight and parallel to the 
longitudinal axis of the segment. These prominent crests on the segments present 
in general the same effect as the combs on the proximal pinnules of the comasterids, 
but the outer edge is straight so that they are in shape oblong with the corners rounded, 
and they are situated on the side of the segments toward the arm tip instead of on the 
opposite edges as in the comasterids. The pinnule is slender, evenly tapering, flagellate, 
and flexible. 
P, is 12 mm. long with 18 segments of which the first three are twice as broad 
as long, the seventh is about as long as broad, and those following gradually increase 
in length, the distal being twice as long as broad. The pinnule is slightly stouter basally 
than P,, tapers more gradually, and is less flexible. It tapers gradually to a point, and 
there is no modification of the segments. 
P, is 10 mm. long with 20 segments and resembles P,; P, is 12 mm. long with 19 
segments; P, is 12 mm. long with 18 segments, very slightly stouter basally than Py. 
The pinnule increases slowly in width to the fifth and sixth segments, the seventh 
tapers strongly distally; and the terminating segments are slender. Viewed dorsally, 
the first two segments are very short, the fourth is about as long as broad, the seventh 
is about twice as long as the central width, and those following soon become about four 
times as long as broad. The fourth-seventh segments have their ventrolateral edges 
produced and broadly rounded, these flanges serving as a protection for the gonad. In 
lateral view the fourth-seventh segments are seen to be broadened, this broadening 
being greatest on the fifth. The seventh and eighth taper distally, and the ninth and 
following are slender. 
