PART 5 A MONOGRAPH OF THE EXISTING CRINOIDS 697 



brachials are much larger and are irregularly quadrate. The first syzygial pair (com- 

 posed of brachials 3+4) is slightly longer interiorly than exteriorly, and about as broad 

 as the median length. The next five brachials are almost oblong, and about half 

 again as broad as long. The following brachials become almost or quite triangular, 

 about as long as broad, and gradually wedge-shaped and elongate distally. The 

 distal edges of the brachials are slightly produced and finely spinous, giving the profile 

 of the arm a regularly serrate appearance. 



Syzygies occur between brachials 3+4, 9 + 10, and 14 + 15, and distally at intervals 

 of 2 (rarely 3) muscular articulations. The width at the first syzygy is 1.0 mm. and 

 the length from the IB^ to the second syzygy 7.0 mm. 



In the type specimen PI is 10 mm. long with 20+ segments, slender but not at- 

 tenuated; the first segment is short, the second is about as long as broad, the fourth 

 and fifth are twice as long as broad, and the distal are about four times as long as broad. 

 The elongated segments have slightly produced and overlapping distal ends which 

 are armed with very fine spines. P 2 is 8 mm. in length, with 13 segments, of which the 

 first is broader than long, the second is about as long as broad, the third is twice as 

 long as broad, and the remainder are much elongated with produced and finely spinous 

 ends. It bears a gonad. P 3 and the following pinnules are similar to P 2 . After P 5 

 the gonads gradually become smaller, disappearing after P 10 . 



In another specimen from Albatross station 2853, P t is 14 mm. long with 30 seg- 

 ments; P 2 is 8 mm. long with 15 segments; P 3 is 7 mm. long with 13 segments; P 4 is 

 7 mm. long with 12 segments and the distal pinnules are 9 mm. long with 21 segments. 



Remarks. In all but two cases this species has been dredged together with large 

 numbers of Florometra asperrima, the young of which it much resembles superficially. 

 The very long PI composed of more elongated segments and the distal intersyzygial 

 interval of only 2 muscular articulations serve at once to distinguish it. 



From Fariometra parvula, which occurs similarly associated with Florometra 

 asperrima off the coast of southern California and southward, it is readily told by the 

 low hemispherical instead of conical centrodorsal and the much shorter P 2 , which is of 

 the same length as P 3 and bears a gonad. 



Localities. Albatross station 3330; north of Unalaska (lat. 5400'45" N., long. 

 166 53'50" W.); 642 meters; temperature 3.22 C.; black sand and mud; August 21, 

 1890 [A. H. Clark, 1936] (1, U.S.N.M., E. 1141). Type locality. 



Albatross station 3331; north of Unalaska (lat. 5401'40" N., long. 16648'50" 

 W.) ; 640 meters; mud; August 21, 1890 (1, U.S.N.M., E. 1142). 



Albatross station 3338; between Unalaska and Kadiak Gat. 5419'00" N., long. 

 15940'00" W.); 1142 meters; temperature 2.95 C.; green mud and sand; August 28, 

 1890 (7, U.S.N.M., E. 1138). 



Albatross station 3340; east of the Shumagin Islands (lat. 5526'00" N., long. 

 15526'00" W.) ; 1270 meters; temperature 2.67 C. ; mud ; August 29, 1890 (1, U.S.N.M., 

 E. 1140). 



Albatross station 2853; south of the Trinity Islands, Alaska Gat. 5600'00" N., 

 long. 15420'00" W.); 291 meters; temperature 5.00 C.; gray sand; August 9, 1888 

 (2, U.S.N.M., E. 1143). 



Albatross station 2858; southwest of the Kenai peninsula, Alaska Gat. 5817'00" 

 N., long. 148 36'00" W.); 420 meters; temperature 4.33 C.; blue mud and gravel; 

 August 24, 1888 (1, U.S.N.M., E. 1139). 



