144 K. MITSUKUFJ : STUDIES ON 



ment can still be recognized. Thkel expresses a great deal of 

 uncertainty as to the condition of the dorsal appendage, bnt 

 finally comes to the conclusion that there are both pedicels and 

 papillae. My conclusions, after examination of a large number of 

 specimens, are as follows : In the dorsum there are no appendages 

 whose end-plates are as large as those of the ventral pedicels. 

 Ent there seem to be differences in the reduction of the size. 

 Some dorsal appendages have well-formed end-plates, and their 

 ends may have sucking power. Others are more strictly papilla- 

 like, and have very small end-plates. I can not be sure of a 

 single case where a dorsal appendage is absolutely without any 

 end-plate. My conclusions are therefore very much like those of 

 Thkel. 



Calcareous deposits consist of an internal layer of buttons 

 and an external layer of tables. Buttons ai'C smooth and have 

 mostly three pairs of holes. Their margin is not much crenated. 

 The table from an adult individual from Tosa (8 cm. long in 

 alcohol) have disks both smooth and spinous on the margin. The 

 crown is very characteristic with the central circular aperture and 

 eight or more teeth projecting outwards. Tlie spire is formed of 

 four colunms with one transverse lioam. It has already been 

 noticed by Thkel in specimens from the Philippines that there 

 are two kinds of tables. He says : " scattered among the common 

 tables with the wide annular apex of the spire provided with 

 eight to ten teeth, others are found witli their spire much more 

 tapering towards the apex which becomes very narrow and com- 

 paratively inconsiderable" (1880, p. 180). I find that this is on 

 the whole the case with younger individuals. In an individual 

 from Tosa, there are tables that are conspicuous by their larger 

 size but have smaller crowns as obsei'ved bv Thkel. As in- 



