I05 
d- arm bases perfectly smooth; synarthrial tubercles, if prcseiU, narrow 
and conical; P, much shorter than P,; elongated proximal pinnules 
more slender, with the component segments more elongated, beyond 
the seventh to tlie tenth twice as long as broad, and distally three 
times as long as broad 
e' narrow and conical synarthrial tubercles present; 1',, 2 mm. to 
3 mm. longer than P^; proximal pinnules stiff and wiry; habit 
robust; 45 — 47 arms (sou th e r n J apa n) ^otoi 
e- no synarthrial tubercles; P., 0.5 mm. to 1.5 mm. longer than P, ; 
proximal pinnules delicate; habit slender and delicate; less than 
42 arms 
f 34 — 42 arms i 10 mm. to 120 mm. long; cirri 30 mm. long with 
29 — 35 (usually 33) segments; P^ and P., with 31 — 34 segments; 
division .series and arms as far as the third brachial thickly 
sprinkled with minute white dots (east coast of India) . ciliata 
{• 29 arms about 85 mm. long; cirri 15 mm. to i8 mm. long 
with 23 — 29 segments; P^ and P., with 22 — 25 segments; division 
series and arm bases without white dots (southeastern 
Africa and M ad agascar) afra 
I. DichroDietra temiicirra A. H. Clark. 
A. H. Cl.VRK. Ann. and Mag. Nat. Hist., series 8, vol. 10, 191 2, p. 34. 
Stat. 318. 6° 36.55., ii4''5s'.5E. 88 Metres, i Ex. 
Stat. 320. 6°5'S., ii4°7'E. 82 Metres. 25 Ex. 
The centrodorsal is low hemispherical with very sloping sides; the dorsal pole is slightly 
convex, flat, or very slightly concave, 1.5 mm. to 2.5 mm. in diameter; the cirrus sockets are 
arranged in two, or in two and a partial third, irregular and crowded marginal rows. 
The cirri are XIX — XXVIII, 25 — 28 (usually 26), 20 mm. to 25 mm. long, slender 
and delicate ; the tenth-twelfth (usually the twelfth) is a more or less marked transition segment ; 
the first segment is very short, the second twice as broad as long, the third slightly broader 
than longf, the fourth from half again to twice as long as the median 
diameter, the fifth from two to two and one half times as long as 
broad; the following to the ninth, tenth or eleventh are similar; the 
remainder are slightly shorter, about half again as long as broad; Fig. 5. 
the tenth-twelfth and following bear prominent triangular median ''""'' "^'^n", " """', '°"' 
fc> r o a specimen oi Dic/iromt/ra Iciiiti- 
spines; after one or two segments these spines occupy about half of «>/.; from stat. 320. x 2.(Cour- 
... tcsy of the f.S.N.itional Museum). 
the mid-dorsal line; the anterior (distal) margm stands out vertically, 
and is from one half to one third as long as the recumbent side; the hypothcnuse, from the 
apex of the spine to the proximal base, is straight, but its proximal end may be marked by 
a slight tubercle, or the hypothenuse may be slightly concave, leading from the distal spine 
SIBOOA-EXPEDITIE Xl.Ili. '■♦ 
