NOTES ON OKGOPSID CKPIIALOFODS FOUND IN JAPAN. 



ior 



proximally the web becomes broader, but finally terminates in a free, acute,, 

 retroverted point. A series of connective suckers, comprising about eleven 

 suckers and fixing tubercles, begins to occur at about two-thirds the length, 

 of tentacle from base and reaches up to the proximal part of club. 



Tentacular suckers, excluding the connective ones, may be divided 

 into two groups, each consisting of about five series : (i) Suckers of the 

 hand portion, which are highly variable in size, those of the median series, 

 being from six to twelve times as large as those of marginal series, while 

 those of submedian series are about half as large as those of the median 

 series. (2) Suckers of the distal portion, which are practically serial con- 

 tinuations of those of the hand portion and which are numerous, minute, and 

 about equally sized, being smaller than marginal suckers of the hand portion. 



Largest tentacular suckers short, pail-like in shape, with a very wide 

 aperture ; horny ring with about fifty or more fine, acute and inwardly 

 directed teeth along the whole margin ; interdental spaces nearly as wide as 

 the teeth at base. Suckers of ventral submedian series and some proximal 

 ones of the hand portion characteristically differ from all others in that they 

 are of a somewhat quadrangular contour and the fundus of their hollow are 

 raised to about the level of the aperture. Their horny ring is provided,, 

 along the entire edge, with about thirty, thick, triangular, outwardly 

 directed teeth, the points of which inclose a space of a quadrangular shape,, 

 the four teeth at the corners ofthat space being thicker and longer than 

 the rest. 



The luminous organs of the mantle are not quite regular in distribu- 

 tion. Nevertheless, the edge of the mantle-opening always shows nine 

 small luminous organs along the emarginated part, and more laterally four 

 slightly larger ones on either side. For the rest, the ventral side of mantle 

 is provided with about forty luminous organs, of which the posterior ten 

 are smaller than those more anteriorly situated. On the dorsal side, there 

 are found about as many luminous organs as on the ventral side, but all 

 are smaller in size ; especially small are the twenty-four situated in the: 

 median region. 



