466 M. FOSLIE. 



cells of the perithallic layer vary greatly in size, as is often the case in calcareous algae 

 burdened with animals. They coincide, however, in the main with the species in question. 



Therefore, also these four specimens in my opinion must be referred to L. fruticulosum, 

 and are so closely connected with f. crassiuscula that in fact they probably only represent an 

 outer limit of this form. A solitary specimen from the most southern part of the Maldive 

 group, Addu atoll, is perhaps referable to the same species. It seems to have been dead 

 when picked up from a depth of about 40 fathoms, but as sterile and not typical it cannot 

 be determined with certainty. 



At the Maldives the species apparently occurs in the sublittoral zone and under much 

 the same conditions as in most other places. It is not known with certainty from what 

 depth this plant was dredged in Male atoll, but in S. Nilandu, " an atoll somewhat similar 

 to Male," f clavulata was obtained at 19 and 35 fathoms, thus rather deeper than for instance 

 in the Gulf of Siam, where it was brought up from 9 fathoms. Indeed f. clavulata appears 

 frequently to descend deeper than i. crassiuscida. Both forms are provided with reproductive 

 organs in January, especially sporangia, while carpospores are scarce. 



Locality. The Maldives : Hulule, Male atoll (f. crassiuscula and a small specimen of 

 f clavulata); S. Nilandu (f. clavulata); and Addu atoll (uncertain). 



Genus Lithophyllum Phil. (Fosl. emend.). 



3. L. Eeinboldi A. Web. et Fosl. (Plate XXIV. fig. 4) in Vidensk. Selsk. Skr. 1901, no. 1. 

 In the collection there was a well-developed typical specimen of this species from the 



Laccadives, attached to an oyster-like shell, and another and quite young one, sticking to 

 a piece of coral. A single specimen from the Maldives (Plate XXIV. fig. 4) bears a few 

 young branches of Goniolithon frutescens, which shows that both species probably appear 

 gregariously in the same habitat. 



It seems as if this species partly grows in the lower part of the littoral zone, partly 

 in the upper part of the sublittoral zone, but apparently not descending to any considerable 

 depth. At the Laccadives the plant is furnished with sporangia towards the end of July, 

 and at the Maldives in the latter half of April. 



This species appears to be widely dispersed in the Indian Ocean. It has been known 

 for a long time from Samoa and Zanzibar, but was not described until collected by Madame 

 A. Weber — van Bosse on Moearas-reef, east coast of Borneo, and at Banda during the Siboga 

 expedition. It is also known from the Tami islands, New Guinea (L. cer'ebelloides Heydr.), 

 and the Hawaiian islands in the Pacific Ocean. 



Locality. The Maldives : Hulule, Male atoll ; and the Laccadives : Minikoi atoll. 



4. L. craspediurn Fosl. 

 New or crit. calc. Alg. p. 26. 



f. compressa Fosl. (Plate XXV. fig. 1). 

 Calc. Alg. Funafuti, p. 7. 

 {. abbreviata Fosl. (Plate XXV. fig. 2). 

 Calc. Alg. Funafuti, p. 7. 



