MELOCRINIDA® (ROEMER) 1855. 
Monocycuiic. LowrER BRACHIALS, WITH WELL DEFINED INTERBRACHIALS BETWEEN THEM, 
FORMING A PART OF THE DORSAL CUP. RADIALS IN CONTACT ALL AROUND. 
Analysis of the Genera. 
ie 
THE SYMMETRY OF THE DORSAL CUP DISTURBED BY ONE OR MORE 
i, DEMIS Go p 6 0 0 0 6 5 OO oY SB of 5 5 oO 6 
A, BASALS FIVE; COSTALS TWO. 
a. First costal hexagonal. 
Arms uniserial ; interbrachials and interdistichals numer- 
ous. Ventral disk composed of very small, irregular 
plates; Basalsismalll’=2) 2) cucu) on i teen 
Arms biserial, basals very large, otherwise resembling 
CU PGHOS 3 9 1 6 9 6 5 9 & 6 a 5 Bo 
b. First costal quadrangular. I 
Arms uniserial; interbrachials few; ventral disk com- 
posed of large plates . . - +--+ +--+ ++. © 
B. BaAsALs FOUR}; COSTALS TWO. 
a. First costal hexagonal. 
Arms uniserial, arranged in groups; simple or bifurcat- 
ing, distichals two to four, calyx of moderate size. . 
Arms long, branching often; palmars and arm joints 
very short, deeply interlocking. Distichals five and 
upwards. Calyx very large; lower palmars partly in- 
cluded in dorsal cup, interbrachials very numerous’. 
The rays extended into five tubular trunks, from which 
biserial arms are given off from the outer sides all the 
WEN uOUNP IS. 6 Oo 5 50 6 9 6 6 6 8 Oo Oo 
C. BASALS THREE; COSTALS TWO. 
Arms biserial, simple from their origin; interbrachials 
few, an anal plate interposed within the first range . 
Tale 
SYMMETRY OF DORSAL CUP UNDISTURBED BY ANAL PLATES. . . - 
A. BASALS rouR; COSTALS TWO. 
a. Arms biserial. 
Arms simple; arranged equilaterally around the calyx ; 
seh) Clete ase G solu 9G 9p Jos O° OF vaso 
Arms dichotomous; basal cup inverted; interbrachials 
LEN fitch ty See esse Wo hon sBe Ge ach iee ts Boao 
B. BASALS THREE, SMALL; COSTALS TWO, THE FIRST QUADRANGULAR. 
a. Arms simple. 
MELOCRINITES. 
Glyptocrinus, 
Periglyptocrinus. 
Stelidiocrinus. 
Mariacrinus. 
Scyphocrinus. 
Melocrinus. 
Macrostylocrinus. 
DOLATOCRINITES. 
Technocrinus. 
Corymbocrinus, 
