JAPANESE ASTEROIDEA : 117 



plate and the terminal extremity, is a somewliat smaller si^iuelet, pointing 



in the direction of the prolongation of the actinal margin of the plate. 



"Seven cribriform organs are present in each interbrachial arc. They 



are narrow and well defined, and their structm*e is papilliform. (See PL 



xxvm. fig. 8.) 



"The ambulacral fmTows are narrow and straight, almost completely 

 <?losed in by the overarching adambulacral plates and spines, the tube-feet, 

 wliich are arranged in simple x^^ii'Sj being entirely concealed from view. 

 The adambulacral plates are about liaK as broad as long, but diminish in 

 size as they proceed outwards, and form along the ray triangular promin- 

 ences projecting into the fm-row. Each plate bears tlu*ee or four spines, 

 rather short, rapidly pointed, more or less compressed, invested with mem- 

 brane, arranged in line along the fmTow margin of the plate, and sometimes 

 ■oblique to the com-se of the furrow. The roAv of spiuelets can be raised at 

 a right angle to the sm-face of the x^late, so as to allow the tube-feet to be 

 protruded. Traces of an aborted secondary or external spinelet, represented 

 by a mere granule, may be detected at the adorai extremity of the adam- 

 bulacral plate, away from the fm-row series. 



" The mouth-x^lates are moderately large, the inner margins which fall 

 in the median sutm'e being elevated so as to form a rounded elongate tuber- 

 ■cular protuberance, the lateral margins being fi[attened out. Their armatm-e 

 consists of seven or eight mouth-spines on each plate, similar to those con- 

 stituting the armatm-e of the adambulcral plates excei^ting the innermost one, 

 which is much larger and stouter. Two large spines are thus conspicuous 

 at each mouth-angle, and are directed towards the centre, the series entirely 

 «losing the actinostome, which is remarkably small. The small mouth-spines 

 upon the margin of the plate interlock with those of the adjacent mouth- 

 bangle, and form a continuous series with the armature of the adambulacral 

 plates. The rudiments of a secondary mouth-spine, represented by a thorn- 

 like gi-anule, occm- on each i^late, near the median sutm-e, and at the liighest 

 portion of the keel. 



" The actinal interradial areas are triangular in outline, flat, extensive, 

 and covered with imbricating scales of more or less regularly symmetrical 



