82 REPORT ON A PROBABLE CALCAREOUS ALGA 



show a marked feature of growth as a living organism, since they appear normally 

 attached to shell fragments and what seem to be the remains of crinoid ossicles. 

 They possess a distinct wall to each thread-like cell, and the character of the wall is 

 such that it could not possibly have resulted from infiltration. These tubular and 

 tufty organisms occur in a series of slides cut from the pebble of a limestone breccia 

 containing Archceocyathince, and are closely related to the before-mentioned Epiphyton 

 fldbdlatum, Born. These specimens also bear some resemblance to Von Toll's figure 

 of Confervites primordialis {he. supra cit>), but there the (?) thallus is not distinctly 

 spreading in radial fashion, the tubular structure being more or less parallel ; 

 in which feature it further differs from Bomemann's type figure. Von Toll's text 

 figure of the Siberian organisms also shows a series of transverse connecting-rods 

 which bind the thallus together, but which are absent in Bornemann's specimens, and 

 are exhibited to a slight degree in the present examples.* 



A very close resemblance exists between the present form and Bornemann's 

 generic type, Epiphyton. In the species figured by that author (E. flabellatum) the 

 thallus is fan-shaped and irregularly, alternately grouped to form comparatively large 

 spreading masses. In the Antarctic species— which specimens, by the way, are all of 

 smaller dimensions — the thallus is less complex, nearly always consisting of isolated 

 tufts. It has a habit of nestling within or growing upon calcareous organisms 

 similar to that of Bornemann's species. 



The only other organism with which the genus Epiphjton could be reasonably 

 compared is Solenopora ; which has of late years been shown to have a strong claim 

 to relationship with the calcareous algse.f In fact, at first sight, it seemed nearest 

 allied to that genus. In some features the two genera show certain resemblances, as 

 in the fascicular grouping of thread-like cells and their division by sparsely distributed 

 horizontal partitions ; but the parallel or elongately radial character of the former 

 affords a distinctive feature between the two kinds of organisms. Solenopora, 

 moreover, never shows, so far as known, the short radial, fascicular habit of Epiphyton. 



DESCRIPTION OF THE SPECIES 



Genus- — Epiphjton, Bornemann, 1887 (? Confervites, Von Toll, 1899) 

 Epiphyton fascicidatum, sp. n. (Plate I, Figs. 1-3) 



Thallus fasciculate and fan-shaped ; consisting of radial and branching tubes ; 

 often occurring in isolated tufts, but normally growing in alternate clusters of two 

 or many more, j Tubes irregularly cylindrical, constricted at intervals and interrupted 

 by more or less horizontal partitions, disposed in fan-shaped groups ; the constrictions 

 impart a digitate character to the thallus. Extremities of the tubes sometimes 

 widening and bluntly truncated. Thallus often fiat or subconvex at the base, owing 

 to its habit of attaching itself to hollow surfaces ; rounded or dome-shaped on the 

 distal surface. A transverse section of the thallus shows it to be thick and radial in 

 structure. Cells in cross-section massed, closely adpressed, subrounded to polygonal. 



* It is probable that Von Toll's so-called Confervites primordialis is really referable to Epiphyton, 

 and not to Confervites, considering the habit of growth shown in his pi. viii, figs, c and d, and his 

 description that it grows in tufty masses on the Archceocyathince of the Cambrian limestone of 

 Torgoschino. 



t " On the Structure and Affinities of the Genus Solenopora," Geol. Mag., Dec. 4, 1894, p. 145. 



j The habit of growth makes it appear a microscopic facsimile of the Cambrian Oldhamia 

 antiqua, Forbes. 



