1 1 



The species attaches itsef to corals <>r other hard objects, developing a feeble crust 

 which attains a thickness of up to aboul 2 mm., frequently however less. From this crust 

 more or less crowded branches are developed. The Iatter are either simple or subdichotomously 

 divided, with short axes, partly increasing in thickness upwards, partly and rather seldom not, 

 or with somewhat spherically thickened ends. The branches are 1,5 — 2 or occasionally up to 

 3 mm. thick, and thej are often knotty. 



A vertical section of the crustlike part of the plant exhibits a rather slightly developed 

 hypothallic layer, composed oi elongated cells which are up to about 20 <j.. long, frequently 

 however shorter. In a longitudinal section of a branch the medullary hypothallium is formeel 

 of cells most commonly 1'., — 2 times longer than broad, or 10 — 18 ij.., occasionally up to 22, 

 generally however 12 — 16 p.. long and 7 — 11 <j.. broad. The perithallic cells are 6 — 10 u.. 

 square or up to about 14 u.. long. Irregularly alternating, long and very short, cells are seldom 

 seen in the medullary hypothallium, as well as in the perithallic layer. Besides appear in both 

 the said layers, particularly however in the perithallic one, square and oblique intermediate 

 cells 2 — 4 ij., in diameter. 



The only reproductive organs known are sporangia. They are 50 — 65, now and then 

 up to So y.. long by a breadth of 30 — 40 or up to about 45 u.. 



1 considered 1. c. the species in question to be a well marked one. It has, however, 

 been stated that the species of this genus at present known are much varying and often not 

 easily recognizable in their most extreme forms. PI. VIII, fig. 15 represents a part of the type 

 specimen of this species. It is burdened with several extraneous objects, which are partly covered 

 with crustlike formations of tissue. The plant is as vet but little known, as till now only a few 

 specimens have been collected. These are even from rather widely distant areas. However, it is 

 mnst probably to be maintained as an independent species. It partly approaches to A. erythraeum, 

 partly it is not easily distinguished from A. timorense, the species last described. It is separated 

 from the former in the main by its thinner branches and frequently shorter cells as well es 

 smaller sporangia. On the other hand it seems to be more closely allied to certain forms of 

 A. timorcn$L\ particularly somewhat densely branched ones, but the Iatter species apparently 

 always develops itself freely at the bottom and generally exhibits larger cells and sporangia. 



Of the two specimens in the Siboga collection, especially that from New Guinea agrees 

 well with A. Schmidtii (PI. VIII, fig. 17). This is also the case with the other specimen but 

 lor its exhibiting cells which are often a little larger than in the former one (PI. VIII, fig. 16). 



Occurrence: Only one specimen brought home from each of the stations above quoted. 



Area: North Pacific: The Gulf of Siam : Indic : The Maldives. 



