538 CORALLINACEAE. 



Lithothamnium Ungeri Kjellm. has been reported from the Challenger Bank by 

 H. B. Bigelow (Proc. Am. Acad. Arts & Sci. 40: 587. 1905), but the type of this 

 species was from Norway and its occurrence in Bermuda is improbable. 



Melobesia farinosa Lamour. forms thin, delicate, whitish, suborbicular, 

 calcareous crusts a line or less broad (but often confluent) on various algae, 

 such as Padina, Dictyota, Sargassum, etc. The crusts in sterile parts consist 

 of only a single layer of cells. The minute hemispheric conceptacles are ^^x~tt 

 of a line broad, are often crowded, and show a single central ostiole. 



Melobesia bermudensis FosL, a species known to the writer from descrip- 

 tion only, is said to form crusts of irregular outline and indefinite size on 

 limestone. The primary crusts consist of a single layer of cells and are about 

 yL. of a line thick, but often one crust overgrows another until five or six may 

 be superposed, with a thickness of y^ of a line, a habit not exhibited by M. 

 farinosa. Bermuda (Farlow) • apparently endemic. 



Lithophyllum pustulatum (Lamour.) Fosl. is found in situations similar 

 to those favored by Melobesia farinosa, which it often accompanies and some- 

 what resembles. It has, however, a larger, thicker, firmer thallus and larger 

 conceptacles, the thalli being 1-5 lines broad and the mammilliform concep- 

 tacles \-^ of a line in diameter. 



Lithophyllum bermudense Fosl. & Howe, forms crusts i-1 line thick on 

 calcareous pebbles, showing occasional wart-like excrescences, most of which 

 are caused by its following the inequalities of the substratum. With occa- 

 sional foreign. inclusions and its own older strata it becomes 4 lines thick in 

 places. A vertical section of decalcified material shows numerous (usually 

 30-40) layers of mostly ellipsoidal and vertically elongate cells (1-6 times as 

 high as broad), which are arranged in regular horizontal strata as well as in 

 vertical rows. The conceptacles are little prominent and are ^— y of a line in 

 diameter. Type from Spanish Point (Hoive). 



Goniolithon decutescens (Heyd.) Fosl. in litt. (GJ spectabile Fosl.) is 

 a frutescent much branched plant, forming depressed-liemispheric cushions 2-5 

 inches high and 5-12 inches broad, light rose-red in younger parts when living, 

 soon decolorate or chalky white after collection. Its branches are terete or 

 subterete, mostly 4-1 line in diameter, crowded, subfastigiate, mostly some- 

 what curved, intertangled and much anastomosed, especially in the lower parts. 

 Originally, there is a horizontal basal crust from which the first erect or sub- 

 erect branches arise and by which it is attached, but this soon becomes over- 

 grown and inconspicuous and is often not shown in specimens as ordinarily 

 collected. Plants or fragments of plants primarily attached may also become 

 free and undergo further development in an unattached condition. A thin 

 translucent cuticle is often irregularly exfoliated, a character that suggested 

 the first-published specific name. A radio-longitudinal section" of a decalcified 

 branch shows rather firm-walled cells in erecto-patent outwardly curved rows, 

 those of the medullary region about twice as long as broad and in rather 

 obvious arcuate strata. Conceptacles, which are infrequent, occur near the 

 tips of the branches, and are hemispheric, mammiform, or conic-mammiform. 



