52 ART. 4. — I. IKEÜA : 



are distributed uumeruus tabular or perforated papill* (Fig. 89); 

 the upper or free edge of these is guarded by a row of very 

 small chitinous teeth. 



In the individuals which I regard as the female, not only 

 the shield itself, but also the calcareous papillae on it, are much 

 smaller than in those which I regard as the male. Besides, in 

 the former case all the jDaj^illoe are nearly of the same size. Some 

 individuals are characterised by a peculiarly modified shield ; the 

 calcareous papillœ found at the apex of such shields are elongated 

 into long processes of a deep brown color. Quite a similar feature 

 was described by Sluiter in connexion with the shield of C. 

 javanicum. 



Clœosiphon japoiiiciüii must be regarded as a distinct species 

 differing in several important points from the hitherto known 

 species, viz., C. aspergillum, C. mollis and (J. java/iiaum. It 

 differs from C. aspergillum in the irregular forms of its calcareous 

 papilhe, in the structure of its skin-papillse (of the introvert-basis 

 as well as of the body proper) and in having the warts and the 

 perforated papilhe. Neither C. mollis nor C. javanicum have the 

 two structures last mentioned. C. mollis may be distinguished 

 from Ö. aspergillum by the presence of very small hooks and the 

 absence of eye-spots, — points of difference which exist also between 

 C. mollis and the present species. Lastly, the differences between 

 C. javanicum and the present species are most remarkable ; in 

 the former species one edge of the external facet of the calcareous 

 papilla Ijeing said to be considerably raised, and the aperture of 

 the papillary gland on the facet, elliptical in shaj)e. Besides 

 these two points, the characteristic broad form of the hooks and 

 the formation of the longitudinal muscles into bundles are quite 

 peculiar to 6! javanicum. 



