JAPANESE ASTEEOIDEA. 191 



more conical and more separated from one another. The surfaces 

 of the fasciolar grooves are covered with capillary spinelets. 



The superomarginals themselves have a more decidedly angular 

 external edge than in Astr. scoparlus and many other species, and 

 the spines are arranged along this edge, forming a conspicuous 

 row. At the interbrachial angles the superomarginals are twice 

 as high as broad, but at the middle of the arms the height and 

 breadth are very nearly equal. 



Inferomarginals.— The general armature of the inferomarginals 

 is fine and consists of short, flattened, conical spinelets, from 

 which a series of 4-6 large spines and one or two others stand 

 out conspicuous (PI. IV, fig. 66). The most external, or marginal 

 spine is conspicuously larger than the others of the series, and is 

 followed by one spine or by two forming a pair. The series of 

 conspicuous spines lies close to the distal edge of the infero- 

 marginals. 



Adamhulacrals. — There are about six adambulacrals to four of 

 the inferomarginals in the greater part of the arms. There are 

 three spines on the furrow border of each plate, then two and 

 finally one usually. This may be shown by the formula 3:2:1, 

 and may be regarded as the typical case ; but the following 

 variations occur very frequently, viz., 3 : 2 : 2, 3 : 2 : 3. Of the 

 first three the middle one is the longest and the adcentral one is 

 mostly slightly longer than the distal ; of the next two, which 

 are slightly flattened and of nearly uniform thickness along their 

 length, the distal one is thicker than the other and frequently 

 also longer ; the remaining spines are irregular both in size and 

 form (PI. IV. Fig. 66). 



Mouth-plates. — The mouth-plates are rather long and narrow, 



