°4 



several rows of more elongated cells. The. perithallic cells are extremely varying too, from 

 about i2 up to about 60 u. in length. They are nearly always rather narrow when much 

 elongated, and often comparatively broader when less elongated. In addition, the cells are 

 most irregular when the plant grows on an uneven substratum, and new crusts are formed 

 one above the other, or with numerous new hypothallic formations sometimes being even 

 marked coaxial. Very long cells and short ones are frequently to be seen in one and the same 

 section. In this respect L. papillosum to some degree corresponds with Lithophyllum incrustans, 

 which exhibits sometimes a very slightly developed hypothallium with rather short cells, 

 sometimes a vigorous hypothallic layer and more elongated cells in the perithallium. This 

 depends on local conditions and the shape as well as partly also the nature of the substratum. 



The mentioned crust in this collection bears some emptied conceptacles (of sporangia?). 

 They are of about the same shape and size as in L. papillosum, partly, however, a little more 

 prominent, but the value of this character cannot be elucidated from such a scanty material 

 of a much varying form. At any rate, however, there seems to be no reason at present to 

 keep it distinct from the above species. 



Occurrence: Only the mentioned small crust is known from the station above quoted. 



Area: The Mediterranean and the Adriatic. 



c. Ramosa. 



5. Lithophyllum Bamlcri Heydr. PI. XII, fig. 1. 



Corall. in Bei', der Deutsch. Bot. Gesellsch. 1897, p. 412. 



Lithothamnion Bamleri Heydr. Neue Kalkalg. p. 4, t. I, fig. 1 — 3. 



Syn. Perispermum hermaphroditum Heydr. in Ber. der Deutsch. Bot. Gesellsch. 1901, p. 409 '|. 



Stat. 79 l '. Pulu Kabala-dua, Borneo-bank. Reef. 



Stat. 282. Between Nusa Besi and the N.E.-point of Timor. Shallow water. 



I do not hesitate to class with this species a couple of specimens in the Siboga collection. 

 One of thein is very small and young. It is attached to a coral, but it shares substratum and 

 is partially covered with a somewhat stunted Lithothamnion simulans and another calcareous 

 alga which probably represents a stunted form of Lithophyllum oncodes. The other specimen 

 seems also to have been attached at first to some hard object, but has afterwards detached 

 itself. (PI. XII, fig. 1). In habit both specimens fully coincide with the type. Cp. 1. c. t. I, 

 fig. 1 — 3. But as to structure there is a great difference to judge from the description given 

 by Heydrich"). A longitudinal section of a branch is described by him as follows: ''Die centralen 

 Zillen bilden nicht, wie bei der vorigen Species, eine lange und eine kurze Reihe, sondern meist 

 zwei lange Reihen von 1 p.. Breite und sehr verschiedenen Langen, meist 4 — 6 ju.., und eine 

 Reihe quadratischer Zeilen von nur 1 u.. Grosse. Die Schichtungen kommen also hier durch die 

 Aufeinanderfolge von 2 langeren und einer kurzen Zellreihe zu Stande. Die peripherischen Reihen 

 bestehen aus rundlichen 1 — iV 2 u. im Durchmesser fassenden Zeilen mit dichtem Zellinhalt". 



I>ie Entwickelungsgeschichte des Corallineen-genus Perispermum Heydrich. 

 2) F. Heydrich. Neue Kalkalgen von Deutsch Neu-Guinea. (Kaiser Wilhelm's Land)-Bibliotheca botanica H. 41, Stuttgart 1897. 



