clakk: crinoids. 241 



Type Cat. 254 M. C. Z. f from Tokio Bay, Japan, 8-12 fathoms, Alan Owston 

 collection, taken October 22, 1899. 



The great amount of eversion and overlapping of the lower pinnule segments 

 make this species one of the most readily distinguishable of the genus. 



Antedon psyche, sp. nov. 



Centro-dorsal low-hemispherical, bearing thirty to thirty-five cirri, the pole 

 bare ; cirri 7 mm. long, with fifteen or sixteen segments, all slightly longer than 

 wide, remarkably uniform, the articulations somewhat expanded ; there are no 

 dorsal spines, but the opposing spine is prominent; radials visible as a low 

 triangle in the interradial area ; first costals low and wide, deeply incised by the 

 axillary, and with a prominent latero-anterior tubercle ; axillaries broader than 

 long, produced posteriorly, where they rise into a slight rounded tubercle ; the 

 first costals and axillaries are in apposition laterally, but are not laterally flattened. 

 Ten arms 55 mm. long, the first brachial wedge shaped (the shorter side in), 

 the second irregular, and the third squarish ; two following brachials roughly 

 oblong, then quadrate, becoming triangular, longer than wide after the ninth, 

 quadrate again at about the middle of the arm, and much elongate and " dice- 

 box" shaped distally. First pinnule, 4 mm. long, with eight to ten segments, the 

 first squarish, the following becoming progressively elongated ; the pinnule tapers 

 gradually from the base to the tip ; second pinnule 7 mm. long, at the base about 

 as stout as the first, but flagellate distally ; it contains eleven segments, the first 

 shorter than broad, the second longer than broad, the others elongated ; the distal 

 segments have the distal edges set with fine spines ; the third pinnule resembles 

 the second, but is shorter, and the fourth is shorter still, about the length of the 

 first ; the following pinnules become more slender, the distal pinnules being 7 mm. 

 long, very slender, with fifteen to eighteen segments, the first two somewhat en- 

 larged, the first broader than long, the second trapezoidal, and the others greatly 

 elongated and slender. 



Syzygia occur in the third, eighth, and twelfth brachials, and distally at inter- 

 vals of one brachial. . 



Color (in spirits) light pinkish, the lower part of the arms, the calyx, and cirri, 

 white. 



Type Cat. 252 M. C. Z., Japan, probably in the vicinity of Tokio or Sagami 

 bays. Alan Owston collection. 



This species belongs to a small but interesting group of the genus Antedon, 

 the species of which are characterized by small size, small number of cirrus 

 segments, and by having the first pinnule never longer, and usually shorter and 

 somewhat stiffer, than those following; the group comprises such species as 

 Antedon nana, A. briseis, A. minuta, and A. adrestine, and occurs from Amboina 

 and the Tonga islands northward to Japan. The comparatively large number 

 of cirri on a hemispherical centro-dorsal, and the length of the second pinnule 

 (which is much the longest) suffice to distinguish A. psyche from the other 

 described species of this group. 



VOL. LI. — NO. 8 16 



