468 BULLETIN 82, UNITED STATES NATIONAL MUSEUM 



pp. 2, 22 (Mortensen's station 21; notes), p. 69; Kungl. Fysiogr. Sallsk. Handl., new ser., vol. 45, 

 No. 11, 1934, p. 25. 



Diagnostic features. The cirri are short and rather stout, about 30 mm. long, 

 with 23-38 (usually 32-36) segments, of which the longest proximal, the eighth-tenth, 

 are about as long as broad, and the distal, from the eleventh onward, are dorsally 

 sharply carinate or bear inconspicuous spines; P 2 and P 3 are nearly or quite twice as 

 long as PI, 14-20 mm. long, with 15-30 segments, P 3 having fewer segments than P 2 ; 

 P 4 is about as long as PI, or slightly shorter; the 26-45 arms are 110-120 mm. long. 



Except for certain species of Comasteridae this is the largest of the shallow-water 

 crinoids of Japan. The structure of the cirri and arms is essentially as in Dichrometra 

 doderleini, which superficially this species somewhat resembles. It is, however, 

 easily distinguished from that form by the structure of P 2 and P 3 , which are of equal 

 length and size, twice as long as P t , and less stiffened and wiry. The cirri are also 

 proportionately shorter and stouter than those of D. doderleini. 



Description. The centrodorsal is thick discoidal, with a rather small polar area 

 bare. The cirrus sockets are arranged in two or three crowded marginal rows. 



The cirri are XXIV, 31-38 (usually 32-36), rather stout, 30 mm. in length. The 

 eighth-tenth segments are about as long as broad, the others not so long as broad. 

 From the eleventh onward a sharp dorsal carination is developed on each segment, 

 which may take the form of a small spine. The opposing spine is centrally or subter- 

 minally situated, short, not reaching one-half the width of the penultimate segment 

 in height. The terminal claw is somewhat longer than the penultimate segment and 

 is rather abruptly curved. 



The division series resemble those of L. regalis, but IVBr series are developed 

 exteriorly. 



The 45 arms are 110 mm. long and resemble those of L. regalis. 



P! is about 10 mm. long, with 26-30 segments, slender and flagellate. P 2 and P 3 

 are 20 mm. long, slender, though stiffer than PI, with, in P 2 , 26-30, and in P 3 20-25 seg- 

 ments, of which the third is about as long as broad and those after the fifth are rather 

 over twice as long as broad. P 4 is 9 mm. long, more slender than PI. The distal 

 pinnules are 10 mm. long. The proximal pinnules are more slender than those of 

 L. regalis. 



The color hi alcohol is reddish brown. 



Notes. Dr. Gislen described the single individual from Mortensen's station 21 as a 

 magnificent specimen. The cirri are XXXVIII, 23-26, from 18 to 29 mm. long. No 

 dorsal spines are developed. The opposing spine is small. There are 28 arms 110 

 mm. long. P! has about 23 segments, P 2 has 18 segments, and P 3 has 15 segments. 

 P 2 and P 3 are of about equal size, about 14 mm. long. P t is shorter and more slender. 



In the specimen from Bock's station 39, as described by Dr. Gislen, the centro- 

 dorsal is discoidal, with the bare dorsal pole 2.5 mm. hi diameter. The cirri are 

 arranged in two crowded rows. The cirri are XXIX, the proximal with 31-38 and 

 the distal with 27-30 segments, and are 16 to 24 mm. long. The first-third segments 

 have slightly convex proximal and concave distal margins when seen in lateral view. 

 The fourth and following segments slowly increase hi length, becoming about as long 

 as broad on the fifteenth or twentieth. There are no dorsal spines. The opposing 

 spine is small, stout, and blunt, reaching a height equal to one-third the width of the 



