8 9 



In 1862, Woronine made a study of Espera and published a paper on the subject in 

 Ann. Sci. Xat. sér. IV. torn. XVI. Bot. p. 208. He discovered large stretches of it spread over 

 the sea-bottom in the neighbourhood of Antibes and he was therefore able to observe the 

 plant in its different stages of development. It is very variable in habit, and only one stage 

 of its growth is represented in Decaisne's diagnosis. 



Woronine describes the plant in its young condition as consisting of filaments dichoto- 

 mouslv branched above and buried at the base in the substratum, and emitting very fine, 

 almost colourless rootlets. The development of the perfect stem is described as follows : "La 

 fronde de X Esp era présente a un endroit un gonflement, duquel sortent, vers Ie haut ainsi 

 que vers Ie bas, des hlaments entièrement libres et qui au commencement ne différent d'abord 

 entre eux d'aucune maniere. Sur les filaments du haut, qui se ramifient dichotomiquement, se 

 montrent des ramuscules latéraux, des crampons, pour mieux dire, lesquels, entrelacés les 

 uns aux autres, relient les filaments de la fronde de X Espera en une tige plus ou moins haute 

 et épaisse, qui n'est rien autre chose que Ie stipe du Penicillus" '. The filaments of the stem as 

 well as those of the capitulum are figured by Woronine. 



Thanks to the kindness of Mons. Bornet we have been permitted to study the interesting 

 and extensive series of specimens of Penicillus mediterraneus preserved in Herb. Thuret, 

 representing numerous stages of growth. No one who has had the privilege of seeing this 

 remarkable series can have any doubt as to the validity of the conclusions arrived at by 

 Woronine. While the comal branches of the perfect or stipitate form are thickly encrusted, 

 those of f. typica are but slightly encrusted, with a porose deposit ; and the youngest ramuli 

 are, according to Woronine, green and destitute of calcification until the approach of winter. 

 Woronine describes and figures both annular and partial (i. e. lateral) stoppers (cloisons) formed 

 by the ingrowth of the cell-wall in the upper filaments. The sporangia are still unknown. 



Though Woronine claimed that Espera is congeneric with Penicillus, he omitted in his 

 paper to coin the binomial Penicillus mediterraneus. Thuret appears to be the authority for 

 that combination. Woronine also omitted to figure or to describe clearly the perfect Penicilhis 

 form (fig. 178) of the plant. Consequently J. G. Agardh, who obviously had seen no example 

 of this perfect form and had to rely upon Woronine's figures, maintains Espera as a separate 

 genus on the erroneous assumption that it has no definite properly-constituted stipes like that 

 of Penicillus ; but he admits that it stands nearest to Penicillus. He also believes that it has 

 an affinity with Chlorodcsmis in habit. That genus however is distinguished from Espera by 

 its total lack of calcification - - a distinction of prime importance (see p. 6). 



The geographical distribution of ƒ>. mediterraneus is confined to the south coast of France. 



7. Penicillus Sibogae n. sp. 



Hab. Indic. Siboga Expedition. Stat. 296. Bay of Noimini, South coast of Timor! alcohol 

 specimen. 



Plant (immature?) about 1 cm. long, consisting of a solitary branched calcified fila- 

 ment; resembling Espera or immature plantlets of P. uod ulosus but smaller and more slender. 



SIBOGA-EXPEDIT1E I.XII. I2 



