il6 
2. Cyllometra Dianca (P. H. Carpenter). 
P. H. Carpenter. Bull. Mus. Comp. Zo<il., vol. 9, 1881, N" 4, p. 5 [Antedon sp.). 
"Challenger" Reports. The Comatulae, 1888, p. 226, pi. 44, figs. 2, 3 {Antedon manca). 
Stat. 305. Mid-channel in Solor Strait, oft" Kampong Menanga. 113 Metres, i Ex. 
The dorsal pole of the centrodorsal is flat, 2 mm. in diameter. The cirri are XV, 31, 
about 15 mm. long; the fifth-seventh segments are about as long as their distal diameter; the 
sixth and following have prominent paired dorsal spines which at first are widely separated 
but distally approach each other and merge into a single spine on the last two segments before 
the penultimate. The 19 arms are 60 mm. long, and are arranged on the five rays as follows: 
3(1 + 3); 4(1 -i- 3); 3 (1 + 2); 6(2, I, I, 2); 2; the IlIBr series are all external. P^ is 11 mm. 
long, and is composed of 16 segments. 
3. Cylloinctra disci for mis (P. H. Carpenter). 
As yet we are unable to state with certainty what really constitute the valid specific 
characters in the genus Cyllometra. The number of arms is subject to so much individual 
variation as to be of uncertain value, while the same is true of the length, number of component 
segments and character of the enlarged proximal pinnules. At present we are inclined to regard 
the cirri as offering the best criteria for specific differentiation, though they also are verj- 
variable. But C. albopurptirea and C. gracilis may be readily distinguished from all of the 
other types by a glance at their cirri, and that is something gained. 
The cirri of t)-pical C. disciformis and typical C. tnanca are very different. In both 
the dorsal spines are well developed (as compared with C. albopurptirea and C. gracilis), but 
in C. disciformis they are much longer than in C. manca, while furthermore the earlier cirrus 
segments are elongated, twice as long as broad instead of only very slightly, if at all, longer 
than broad. However, in deep and cold water as a rule the elongated earlier cirrus segments 
of C. disciformis rapidly shorten, so that the character of the cirri approaches that of typical 
C. manca. 
I have before me 56 specimens which 1 have referred to C. disciformis, all from the 
Philippine Islands : 
East of Masbate, 80 fathoms ("Albatross" Stat. 5213; Cat. N" 35314 U.S. Nat. Mus.); 
45 Ex. Of these the largest have arms 95 mm. long; ten have 11 arms, eight have 12 arms, 
six have 1 3 arms, four have 1 4 arms, three have 1 5 arms, two have 1 6 arms, three have 
17 arms, two have 19 arms, and four have 20 arms; one is badly broken, and there are two 
ten-armed young. 
East of Masbate, 80 fathoms ("Albatross" Stat. 5213; Cat. X" 36037 U.S. Nat. Mus.); i Ex. 
East of Masbate, 108 fathoms ("Albatross" Stat. 5212; Cat. X" 35348 U.S. Nat. Mus.); 
3 Ex. These have 16, 18 and 20 arms. 
Xorth Balabac Strait, 58 fathoms ("Albatross" Stat. 5356; Cat. X" 35280 U.S. Xat. 
Mus.); I Ex. 
