174 



ART. 2. — H. MATSÜMOTO : 



Fig. 44. Ampldoplus macraspis. x 9. a. From 

 below, h. Side view of three arm joints near 

 disk, c. Ventral view of an oral angle, d. 

 Ditto. 



acuter than the ordinary ones» 

 and is sometimes placed at a 

 liigher level than the distal 

 oral papillaG (fig. d), but very 

 often forms a continuous series 

 with the latter (fig. a). Some- 

 times, there occur only two 

 genuine distal papillaB (fig. c), 

 besides the comparatively large 

 additional one. The outer- 

 most papilla is very small, 

 often so small as to be almost 

 imperceptible ; the next is the 

 largest of all. These two arise 

 from the adorai shield. Sometimes, a single (fig. a) or paired 

 (fig. d.) very small additional infradental papillae are present, just 

 above and between the pair of the ordinary ones. 



As already mentioned, Amphiodia does not stand intermediate 

 between Ampliiura and Amphioplus, but the last two genera are 

 directly related to each other. In my opinion, the species of 

 Amph'mra with two distal oral papillœ on either side, such as A. 

 cmomala Lyman, A. crassa Kœhlee, A. servata Kœhler, A. grata 

 Kœhler, a. reposlta Kœhleu, A. korece Duncan, A. assimiUs Lüt- 

 ivEN à MoETENSEN, A. cligitula (Claek), t^c. are Amphioplus-Yike) 

 AmpMura, while the present species is a representative of Amphiura- 

 like Amphioplus. The oral angle shown in fig. c more or less 

 reminds us of that of an Amphiura. 



