73 



I II ROSIII OIISHIMA : 



The color is a deep brownish purple 

 all over, somewhat lighter on ventrum 

 than on dorsum. All the viscera 

 are of a uniform purple color, pro- 

 bably due to staining after pre- 

 servation. As to calcareous deposits 

 of the perisome, it may be worth 

 while to note that in the introvert 

 I have found only the rods de- 

 scribed and figured by LUDWIG [24, 

 p. 1238 and Taf. XV., Fig. 15], the 

 lenticular plates characteristic of the 

 species being there totally absent. 

 As to other characters of the species, 

 except as regards the asymmetry of 

 the calcareous ring (textfig. 4) and the arrangement of tentacles 

 (textfig. 1) before enunciated, I have nothing to add to the descrip- 

 tions given by previous observers. 



Textfig. 4. 



Three consecutive segments of tlie 

 calcareous ring of Pimdocutumis 

 africanus, viewed from the axial 

 side. ( x 10). 



Genus JPhf/Hojyfioi'tfs Grube (Ludwig emend.) 



(+ Orcula TrosCHEL). 



LUDWIG [21, p- 1240 — 1241] last defined the genus to have 

 unequal sized tentacles more than fifteen in number, of which the 

 smaller stand alternately with the larger, all or a part of the former 

 forming an inner circle of tentacles. OSTERGREN's suggestion to 

 unite Gratia with the present genus seems to be reasonable, as I 

 already mentioned at the end of Part I of this paper. Moreover, the 

 genus should comprise a Hawaiian species recently described by 

 FISHER [13, pp. 713—715] under the name of Thyonidium alexandri, 

 in which ventral interambulacra are naked. Consequently, in my 

 opinion, the genus should be defined as follows : — 



