NOETH PACIFIC OPHIURANS IN NATIONAL MUSEUM CLARK. 287 



been compared with European and West Indian specimens, and no 

 differences, other than those of age and individual diversity, have 

 been found. I have also examined specimens of Liitken's and Mor- 

 tensen's three Panamic species (dispar, plana, and excavata) and 

 believe they are quite distinct. The north Pacific specimens of loveni 

 show great diversity in the relative size of the different arms, but, as 

 a rule, full-grown specimens have one or two of the arms much 

 broader than the others. Thus, a specimen 40 mm. across the disk 

 has the greatest width of each of the five arms, successively, as follows, 

 9, 6, 7J, 6^, and 5 mm. Liitken and Mortensen give this peculiarity 

 as the striking feature of dispar, but I think it is probably a charac- 

 teristic of sexually mature adults of any species in the genus. Its 

 degree of development varies greatly. Two extremes may be given 

 as follows: 



Disk, 22 mm. across; arms successively 8, 3, 3, 5, and 3 mm. broad. 



Disk, 30 mm. across; arms successively 5, 4, 4J, 3^, and 4 mm. 

 broad. 



The geographical range of loveni is noteworthy, for, although it does 

 not appear to be an Arctic or subarctic form, it occurs in the north 

 Atlantic from the coast of Norway southwestward along the east 

 coast of the United States to St. Vincent in the Lesser Antilles; in the 

 north Pacific from Bering Sea, 57 N., to Timor on the south; and in 

 the Indian Ocean to the Laccadive Islands on the west. Yet it is 

 apparently wanting in the Panamic region and in the eastern Atlantic, 

 where it is replaced by allied species. 



TRICHASTER PALMIFERUS. 



Euryale palmiferum LAMARCK, Anirn. s. Vert., vol. 2, 1816, p. 539. 



Tricaster palmifer AGASSIZ, Mem. Soc. Sci. Nat. Neuchatel, vol. 1, 1835, p. 193. 



Trichaster palmiferus MULLER and TROSCHEL, Sys. Ast., 1842, p. xiv and 120. 



Localities. Albatross station 4929, Colnett Strait, lat. 30 12' 30" 

 TST.; long. 130 43' E., 84 fathoms, broken shells, coral, pebbles, bottom 

 temperature 74.8, 2 specimens; station 4931, Colnett Strait, lat. 

 30 12' N.; long. 130 43' 40" E., 83 fathoms, broken shells, pebbles, 

 coral, bottom temperature 75.4, 1 specimen. 



In the specimen from station 4931 each radial shield carries a small 

 conical tubercle at its distal end. Such tubercles are wanting in the 

 other specimens. 



GORGONOCEPHALUS CARYI. 



Astro phyton caryi LYMAX, Proc. Boston Soc. Xat. His!., vol. 7, 1860, p. 424. 



Gorgonocephalux cari/i LYMAX, Challenger Oph., 1881, p. 2*il. 



Astrophyton stimpsonii VERRILL, Proc. Boston Soc. Xat. Hist., vol. 12, 1869, 



p. 388. 

 Gorgonocephalus japonicus DODERLEIN, Zool. Anz., vol. 25, 1902, p. .521. 



Localities. Albatross station 2S44, off Alaska, lat. 53 56' N.; long. 

 165 40' W., 54 fathoms, gray sand, bottom temperature 42, 15 



