Filament simpli I uncalcified below, calcified above and branched diobotomously 



in alternatc pla dly trifurcately, slightly inflated below each dichotomy; branches 



constricted al n subtorulose immediately above il and occasionally at intervals 



along th ili. i | i in diam. ; calcareous sheath minutely porose I igs. 181, 182]. 



Th of which we have seen only one gathering, is mixed with Udotea javensis 



and < and was probably dredged up from between 8 and 36 meters, h appears 



immature state of a more highly developed species hitherto undescribed and unknown. 

 Had ii been possible t" maintain De< vïsne's Espera as an independenl genus, we should 

 witho iitation have placed this species in it. But, as Woroninj shewed nearly half a cen- 



tury ago, Espera is nothing but a state of a species of Penicillus, which is now known 

 ,i- P terraneus. Our sp< fig. 181) so closely resembles in its simple halm small 



plantlets of the Espera- state of /'. mediterraneus (luit differs in having the filaments smaller, 

 frequently beaded and often trichotomous), as to suggest the possibility of its being the 

 />/<•;•,; stat»- of an Indian Ocean species of Penicillus. The only species hitherto recorded 

 from that region is /'. nodulosus Blainv. (= /'. arbuscula Mont.), which in its early stage 

 consists of small plantlets of branched and beaded filaments. But the dimensions of those fila- 

 ments are about 300 f* in diameter, whereas in /'. Sibogae they are only about too/üi in dia 

 meter, and the beading is less conspicuous. The two plants, though closely allied, are not 

 conspecific, though they may well be congeneric. There are two points of interest in /'. Sibogae 

 to which attention may be called. In the firsl place, we find in /'. Sibogae instances of trifur- 

 branching, a mode ol ramification which occurs also very rarely in /'. dumetosus and 

 other species, and more commonly in />oodlco/>sis isee also p. 3). In the second place, we 

 have found a solitary instance of lateral cohesion between two adjacent parallel ramuli along a 

 very short distance of their length, viz., 0.5 mm. (Fig. iSi,m. This must probably is a mere 

 chance conglutination due to the simultaneous calcification of the two filaments which happened 

 to be in close and parallel contiguity. But on the other hand it may possibly point to the 

 formation of simple flabellate fronds in a more- mature state of the plant, such as are found 

 in Tydemania, Udotea and Rhipocephalus \ but the evidence is far too slender to allow any 

 definite inference to be drawn from it, and. we are inclined to regard the said cohesion as 

 accidental. Moreover it must be remembered that the successive dichotomies of /'. SU 

 occur in alternate planes, a fact which [joints much more towards the formation of a Peni- 

 cilloid capitulum than of a Udoteoid flabellum. However it is conceivable that /'. Sibogae, like 

 Tydemania, may have the power of producing both capitulum and flabellum. 



Another possibility about /'. Sibogae is that it may be another such primitive Sipho- 



form as Chlorodesmis, from which of course it differs in being calcified and not gre- 



garious. And whereas Chlorodesmis indicates the ancestry of Flabellaria and other green 



genera, 10 P Sibogae might indicate the ancestry of some of the calcified genera 



sample, Penicillus, Tydemania, etc. 



iphical distribution is at present limited to Timor in the Indian ( tcean. 



