No. 6] NEW MELOBESIEAE. 13 



In New or crit. calc. Alg. p. 26 I referred a fragmentan' 

 specimen in Thurets (Bornefs) herbarium from California to L. 

 Yencloi, and shortly after I considered two young specimens also 

 from the Californian coast, collected by Dr. De Alton Sa unders, 

 as belonging to the same species. In the said collection of calca- 

 reons Algae that Prof. W. G. Far lo w kindly sent me I met with 

 older specimens of the same form. It is closely allied to L. Yen- 

 doi, and young specimens are next to impossible to separate from 

 the latter. The diflerences are however shown to be considerable 

 «nough to keep it distinct and, therefore, I allow myself to propose 

 the above name. 



As lately seen in specimens from the Gulf of Siam, L. Yen- 

 dvi in fact shows no tendency to develop excrescences. Very 

 small ones sometimes are formed, or the crust becomes somewhat 

 uneven in an old stage, partly however by growing over small 

 extraneous objects partly trumbling crusts forming small and irre- 

 gular ridges. 



In L. Farlowii on the other hand the crust develops small tu- 

 bercles even in a young stage, and older they become more and 

 more numerons, at length densely crowded but rather irregular, 

 and often anastomosing, attaining a height of about 2 mm. In an 

 old stage the said tubercles or short branches occasionally are 

 provided with fungously thickened ends, or irregular new forma- 

 tions are formed, in part however caused by covering up extra- 

 neous objects. The species then differs much from L. Yencloi *) 

 in habit and approaches L. Marlothii, the latter however being 

 coarser and differing in structure. 



Also with reference to structure the present species is very 

 riearly related to L. Yencloi. The perithallic cells are partly square 

 or rounded, 5 — 7 or up to 9 p. in diameter, partly vertically or 

 horizontally elongated, 5 — 10 /*, or occasionally up to 12 \x long 

 by 4—6 fi. The corresponding cells in L. Yencloi are sometimes 

 a little larger than the average of size quoted 1. c, but in L. Far- 



x ) It is on the other hand a question wehther L. Yencloi and L. åecipiens 

 must not be considered as forms of one and the same species. Some spe- 

 cimens from the West Indies seem to point in this direction. 



