MONOGRAPH OF JAPANESE OPHIÜROIDEA. 9 



Oph'ioleptoplax Claek, 1911. 

 II. Second oral tentacle pores opening entirely within the 

 oral slits. 

 a. Teeth and oral papillae acute, not widened and serrate. 

 Ophioscolex Müller à Tkoschel, 1842. 

 Neoplax Bell, 1884. 

 Ophiostlba Matsumoto, 1915. 

 Ophiomora Kœhler, 1907. 

 b: Teeth and oral papillae widened and serrate along the 

 fi'ee end : 



Ophiohyalus Matsibioto, 1915. 

 Opliiomyxa Müllek & Teoschel, 1842. 

 Ophiodera Yerrill, 1899. 

 Ophioliymen Clark, 1911. 

 Subfamily 2. Ophiohyrsince Matsumoto, 1915. — Oral and 

 adorai shields very thick, intimately joined to each other, the 

 latter being entirely proximal to the former ; vertebrae short and 

 stout, always entire ; wings of the vertebrae very thick laterally as 

 well as dorsally ; vertebral articulation streptospondyline, the arti- 

 cular peg being very rudimentary or entirely absent. 



I. Oral shields absent, except in one interradius ; a single 

 genital slit to each interradius. 

 Ophioschita Clark, 1911. 

 IL Oral shields well developed ; two genital slits to each 

 interradius. 



Ophiophrixus Clark, 1911. 

 Ophiobyrsa Lyiman, 1878. 

 Ophiobyrsella Verrill, 1899. 

 Ophiosm'ilax Matsumoto, 1915. 

 OpMohrachion Lyman, 1883. 



