NOETH PACIFIC OPHIURANS IN NATIONAL MUSEUM CLARK. 155 



AMPHIODIA OCCIDENTALIS. 



Amphiura occidentalis IjYMAN , Proc. Boston Soc. Nat. Hist., vol. 7, 1860, p. 194. 

 Amphiodia ocddentalis Verrill, Trans. Conn. Acad., vol. 10, 1899, p. 313. 



Localities. — Monterey, California, 1 specimen (Lyman's type); 

 Puget Sound, 1 specimen; Kadiak, Alaska, 1 specimen. 



This species has been sufficiently figured by L}Tnan, so that no illus- 

 trations need be given here. The arm spines are the most charac- 

 teristic specific character. The range northward is greatly extended 

 by the discovery of occidentalis at Kadiak. 



AMPHIODIA CRATERODMETA, new species.a 



Disk 8 mm. in diameter; arms about 32 mm. long. Disk rather 

 thick and stout, covered by numerous, coarse, distinct scales, among 

 which the primary plates are not conspicuous. Radial shields about 

 twice as long as wide, closely joined. Upper arm plates somewhat 



Fig. 05.— Amphiodia craterodmeta. 



X C. a, FROM above; 6, from hei.o-\v; c, side atew of three 



ARM JOINTS NEAR DISK. 



variable, broadly triangidar, or diamond-shaped, with lateral angles 

 truncate, or somewhat hexagonal, much wider than long, only 

 narrowly in contact. Interbrachial spaces below well covered with 

 numerous, distinct scales. Oral shields small, rather variable, but 

 usually wider than long and pointed proximally. Adoral plates 

 very large, variable in shape, somewhat triangular in the type, with 

 inner sides concave, but usually they are tetragonal and meet broadly 

 at their inner ends, which are nearly as wide as outer. Oral })apill8e 

 three on a side, subequal, thick and rounded, or the two inner ones 

 may be somewhat pointed. Genital slits rather large. First under 

 arm plate small, wider than long; succeeding plates variable, but 

 generally more or less in contact, somewhat pentagonal and about 

 as long as wide; in the type they are much wider than long. Side 



a KpaTepdc, signifying strong, and 8ifiw, signifying to build, in reference to the com- 

 paratively stout structure. 



