73 



are perceptible in the lower part of the thallus too, i. e. the bottom of the said organs is here 

 very slightly convex and marked by a faintly impressed annular border. This is never seen 

 in M. af/niis, nor in M. macrocarpa. Besides, older specimens of M. Lamourouxii are quite 

 different. The species in question also comes near to M. pacifica, which however is more 

 delicate, with smaller conceptacles ] ). 



Occurrence: Only the three specimens figured are known from the station quoted aboVe. 



Subgen. Li t hop o rel la Fosl. 



3. Mastophora melobesioides Fosl. Fig. 30 — 32. 



Det Kgl. Norske Vidensk. Selsk. Skrifter 1902, Aarsberetning (Trondhjem 1903). 



Stat. 66. Bank between islands of Bahuluwang and Tambolungan, south of Saleyer. 8 to 10 m. 



Dead coral; Halimeda ; Lithothamnion. — The species in question overgrown by 



Lithothamnion fruticulosum. 

 Stat. 81. Pulu Sebangkatan, Borneo-bank. 34 m. Coral bottom and Lithothamnion. — Partly 



uncovered, partly overgrown by Lithothamnion prolifer and Archaeolithothamnion 



erythraeum. 

 Stat. 93. Pulu Sanguisiapo, Tawi-Tawi Islands, Sulu Archipelago. 12 m. Lithothamnion 



bottom. Sand and coral. — Overgrown by Archaeolithothamnion erythraeum. 

 Stat. 106. Kapul Island, Sulu Archipelago. 13 m. Coral bottom. — On Lithothamnion fruticulosum. 

 Stat. 109. Pulu Tongkil, Sulu Archipelago. 13 m. Lithothamnion bottom. — Partly uncovered, 



partly overgrown by Lithothamnion fruticulosum. 

 Stat. 123. North Bay, Biaru Island. 36 — 2701. Stone and Lithothamnion bottom. — Overgrown 



by Lithothamnion fruticulosum. 

 Stat. 133. Lirung, Salibabu Island. Shallow water. — The species in question uncovered. 

 Stat. 240. Banda-anchorage. Lithothamnion bank in 18 — 36 m. — Overgrown by Lithotham- 

 nion fruticulosum. 

 Stat. 282. Between Nusa Besi and the N.E.-point of Timor. 27 — 54 m. Sand, coral and 



Lithothamnion. — Overgrown by Lithothamnion fruticulosum. 

 Stat. 303. Haingsisi, Samau Island. Reef. — Uncovered. 

 Stat. 315. East of Sailus Besar, Paternoster Islands. Up to 36 m. Coral and Lithothamnion. — 



Overgrown by Archaeolithothamnion timorense. 

 Stat. 322. i'/j mile south of Tandjong Lajar, South-coast of Bawean Island. 32 m. Coral. — 



The species in question overgrown by Lithothamnion si mn lans. 



I classed this species 1. c. as a subgenus, Lithoporclla, distinguished from Eumastophora 

 by its irregularly crustlike, undivided and not flexible thallus which is frequently stratified, i. e. 

 one layer of cells with marginal growth on the other. 



The plant forms scaly patches or smaller or larger crusts of indefinite shape which 

 frequently get confluent and at length form partly small, partly even extended incrustations on 

 other calcareous algae, Bryozoa, corals and other hard objects, although it has not vet been 



1) In Melob. Arb. Heydr. p. 19 I remarked in regard to Melobesia pacifica Ileydr. : "Es ist klar, dass diese Alge keine Mdobesia 

 ist, dagegen wahrscheinlich ein neues Genus der Squamariaceen reprasentiert; aber dieselbe als solches aufzustellen scheint zur Zeit doch 

 nicht berechtigt, da ihre Reproduktionsorgane zu wenig bekannt sind". However, in Vidensk. Selsk. Skrifter 1902, Aarsberetning 

 (Trondhjem 1903) I have shown that the plant is a Mastophora and placed it as JA pacifica (Heydr.) Fosl. — Besides, I remarked that 

 "altere Teile vom Thallus aus mehreren Zellreihen bestehen". This is however so to be undeistood that new formations sometimes are 

 developed, one row upon the other, although the cells in certain parts of the thallus can be divided even in vertical direction. 

 SIBOGA-EXPED1TIE I.XI. 10 



