80 



]oi\'ii and A. cremilata) occasionally, however, overlapped; the 

 individuals intermingling in this common region were, as a rule, 

 easily referred at sight to the one species or other, though once 

 in a while an individual was met with whose affinities seemed at 

 first a little dubious«. 



Another closely related species, if it is specifically different 

 from A. Caliciiliis, is A. Suhrii of which I have had authentic 

 material from the Botanical Museum in Berlin for comparison. 



The reason why this species especially is said to be different 

 from A. Caliculiis is, according to Solms, that the segments of 

 the corona superior have about four hair-insertions and that the 

 rays in the disc are united by calcification of the side-walls, but 

 completely separate after treatment with acid, whereas A. Cali- 

 culus according to Solms has the segments of the corona superior 

 with two hair-insertions and the rays even in the living state 

 separate and free. As to the last point I have already shown that 

 this character is scarcely of much importance. And as to the hair- 

 insertions I would also remark that there can scarcely be much 

 difference ; in two original specimens from the Botanical Museum 

 in Berlin which I have examined I as a rule foimd 3 hair-scars in 

 the segments which I saw most distinctly, in one 1 only found two ; 

 several of the segments were somewhat shrivelled and some of 

 them may have had 4 scars. Even then the difference is not so 

 great, as A. Caliculus, according to Solms, sometimes has three 

 scars which were also sometimes found in my specimens. In the 

 number of the rays also, Solms says that there is some difference^ 

 as in the .4. Suhrii we have 25 — 30 as compared with A. Caliculus 

 which only has 22 — 25. To this I may point out that in my mate- 

 rial of the last named species I have found specimens with up to 

 31 rays, most frequently they had about 27. The specimen I have 

 seen in the Brit. Museum of A. Caliculus had 26 rays^). Lastly, 

 I would remark that the stipe in A. Suhrii, in any case on the 

 specimens examined from the Museum in Berlin, has quite similar 

 spindle-shaped swellings as are found in A. Caliculus; this is not 

 mentioned by Solms. 



Therefore I do not think it possible to take A. Suhrii as a 

 species. 



As pointed out in my earlier paper Acetabularia caraibica 

 Kiitz. is a very dubious form. Already in 1901 M. A. Howe has 



^) The specimen drawn by Quoi and Gaimard seems also to have this 

 number! 



