A MONOGRAPH OF THE EXISTING CRIN01DS 87 



is rather longer than broad, and the fifth, a transition segment, is somewhat over twice 

 as long as broad with the distal third highly polished. The next segment is about half 

 again as long as broad and those following decrease in length, after 3 or 4 becoming 

 about as long as broad and so remaining to the penultimate. The transition segment 

 and all the segments following bear prominent and sharp dorsal spines. The opposing 

 spine is blunt, and very small or obsolete. The terminal claw is longer than the penulti- 

 mate segment, and is relatively little curved. 



The disk is unplated. The brachial ambulacra have well-developed plates. The 

 pinnule ambulacra have well-developed side and covering plates. Sacculi are abundant, 

 large on the brachial ambulacra, and small on the pinnules. 



The ends of the basal rays are visible as small tubercles in the intcrradial angles 

 of the calyx. 



The radials are concealed by the centrodorsal. The IBri are short, about 4 times 

 as broad as long, smooth, with the dorsal surface somewhat convex and bearing a large 

 low rounded tubercle in the median line. It is slightly chevron-shaped. The IBr 3 

 (axillaries) are rhombic or almost low triangular, about twice as broad as long, with the 

 dorsal surface moderately convex. The IIBr series are 2, resembling the IBr series. 



There are 13 arms in the type which are 100 mm. long. The first 2 brachials are 

 slightly wedge-shaped with the longer side out. The first syzygial pair (composed of 

 brachials 3 + 4) is rather less than twice as broad as long, with the hypozygal about 

 twice as long as the epizygal. The following brachials are oblong or slightly wedge- 

 shaped, about twice as broad as long, after the twelfth becoming obliquely wedge-shaped 

 and about as long as broad. The arms are rounded dorsally and the distal ends of the 

 brachials are prominent, though there is no overlapping. 



Syzygies occur between brachials 3 + 4, again from between brachials 13+14 to 

 brachials 16+17, and distally at intervals of from 3 to 5 (most commonly 4) muscular 

 articulations. 



PI is 7 mm. long with 16 segments the first 3 of which are rather disproportionately 

 large, about as broad as long, with broad and spinous dorsal keels, the remainder being 

 smaller and more slender, and longer than broad. P 2 is 6 mm. long, more slender than 

 PI and tapering evenly from the base, with the basal segments not differentiated from 

 the others. It is composed of 14 segments of which the first 2 are about as long as 

 broad and those following slowly become elongated. The segments are slightly carinate 

 and are broader at their distal than at their proximal ends so that the pinnule has a 

 notched outline. The following pinnules are similar, but decrease in length to P 8 and 

 then gradually increase distally, reaching a length of 8.5 mm. The distal pinnules have 

 the first segment short, the second about as long as broad, and the remainder gradually 

 becoming elongated, though the length never exceeds twice the width. The distal ends 

 of the segments are somewhat overlapping. 



Locality. Albatross station 4122; Hawaiian Islands; Barber's Point Light (near 

 Honolulu) bearing N. 82 E., 2.2 miles distant; 351-<543 meters; coarse coral sand and 

 shells; July 26, 1902 [A. H. Clark, 1908, 1909, 1912, 1918, 1929, 1949] (1, U.S.N.M., 

 22686). 



History. This species is as yet known only from the type specimen described under 

 the name of Thalassometra fisheri in 1908 and transferred to the genus Parametra 

 in 1909. 



