12 GRAF ZU SOLMS-LAUBACH— MONOGEAPH OF THE ACETABULAEIE.^. 



line. The spore-membranes of our incrusted algse might probably be calcified [a pheno- 

 menon not seldom observed in many other JDasycladece], and in this way give rise to the 

 cell-formation mentioned." With reference to the words placed in brackets, Andrussow^ 

 was not justiiied in their use, since, at the time he wrote them, Acicularia, Chalmasia, 

 and Ilalicoryne, the only genera of Betsy cladew with calcified spore-membranes, had not 

 been investigated with reference to this point. Since the name " miocenica " has been 

 given to another Acicularia, I must name afresh the South Russian fossils, and they may 

 be called Acicularia A^idrussowii. 



Chalmasia antillana is the name by which I shall refer to a plant w^hich I discovered 

 in Herb. Thuret, represented by a few incomplete specimens collected by Agassiz in the 

 West Indies. In habit it agrees with Acetabuloides, of which the disc-chambers are 

 easily separable after decalcification. But it shows on closer examination the characters 

 of Folyphysa ; the corona inferior is absent. The free parts of the corona superior have 

 a peculiar form and terminate in obtuse processes with two or three hair-projections. 

 The calcification is slight and apparently confined to the outside of the membrane. 

 On the sporangial rays there are irregular lime-scales, surrounded by furrows, lying on the 

 outside of the membrane, and somewhat easily loosened with the help of a needle. The 

 cbarac^ter of the genus is to be found in the spores. These are free as in Acetabularia 

 and fill the sporangial ray with their irregular mass ; they are provided with a thick, very 

 strongly calcified membrane, and appear on this account, when seen with a pocket lens, 

 as milk-white, not transparent globules. When these spores are decalcified they show 

 first of all that their membrane, compared with the forms already mentioned, possesses 

 extraordinary thickness, is beautifully and abundantly stratified, and surrounded by a 

 definite, coarse cuticuloid layer. The locus of the lime-incrustation is to be found here 

 in the layers themselves of the membrane, while those of Acicularia, where only the 

 slime mass is calcified, are quite free from it. Again a lid of circular form and consider- 

 able diameter is present. It has, however, a somewhat different form and does not repre- 

 sent a cone-valve inserted from within, but rather it broadens towards the outside so that 

 in optical section the two lateral bounding lines converge towards the interior, and do 

 not diverge as in the other cases. Possibly this stands in connection wdth the remarkable 

 thickness of the spore-membrane, which, if the lid w^ere inserted as in Acetabularia, 

 would necessitate a considerable increase in the volume of the spore to render its falling 

 out possible. For the rest the spores agree down to the minutest details with those 

 of Ralicoryne, with which, however, Chalmasia could not be united owing to the wholly 

 different structure of the shoot (comp. Plate III. figs. 2, 3, 5). 



Of the genus Ralicoryne there are two species known, viz. K. Wrightii, Harv., from 

 the Loo-choo Islands and the Philippines, and R. spicata, Kiitz., from New Caledonia. The 

 first brief description was given by Harvey in October 1859, and then Kiitzing, without 

 knowing of this publication, described the other species as Polyphysa spicata, Kutz., 

 which Souder subsequently, again without knowing of the Harveyan genus, distinguished 

 by the name of Pleiophysa spicata without farther statement. Since then Agardk only 

 has made farther examination of these rare plants ; Cramer had no material *. 



* See note on p. 39. 



