TWO NEW LITHOTHAMNIEAE, CALCAREOUS ALGAE, 
FROM THE LOWER MIOCENE OF TRINIDAD, BRITISH 
WEST INDIES. 
By Marsuaui A. Hows, 
Of the New York Botanical Garden. 
The following are descriptions of two species of fossil calcareous 
algae from Trinidad, submitted by T. W. Vaughan: 
LITHOTHAMNIUM PENNYI, new species. 
Plates 1 and 2. 
Thallus forming irregular nodulose or verrucose concretions 
3.5-5 em. in diameter, the verrucae, knobs, or short branches up to 
5 mm. high, 2-7 mm. broad, obtuse or subtruncate; transverse frac- 
tures of the knobs showing pronounced irregularly concentric, more 
or less plicate lamellae mostly 0.15-0.2 mm. thick; transverse or 
radio-vertical sections of the knobs conspicuously zonate by the 
frequent alternations of large-celled secondary hypothallia and 
small-celled perithallia; cells of medullary hypothallia irregular in 
outline and arrangement, mostly 25-50p high by 13-25y. broad; cclls 
of secondary hypothallia (or of large-celled perithallia?) 14-25y 
high, 13-28y. broad, subquadrate, often broader than high, less com- 
monly higher than broad, distinctly layered in the outer zones, less 
distinctly in the inner; cells of the perithallia minute, subquadrate, 
4-7, high or broad, rather indistinctly layered; conceptacles (tetra- 
sporic) becoming embedded, the cavity 350-600p in maximum width, 
150-200y. in height, the roof usually well defined. 
A single, nearly free specimen in Matchepoorie quarry, longitude 
61° 14’ 35’ W.; latitude 10° 27’ 25’’ N., Trinidad, British West 
Indies, F. W. Penny No. 5, station No. 8301 (lower Miocene). 
Type in U.S. National Museum, Cat. No. 36604. 
Of the hitherto described American fossil Lithothamnieae, Litho- 
thamnium penny is apparently most nearly allied to L. vaughanii 
M. A. Howe! from the Oligocene of the Panama Canal Zone, but 
differs in having a thallus the surface of which is knobbed or ver- 
rucose rather than developing anastomosed branches, in the larger 
1U. S. Nat. Mus. Bull. 103, 1919, p. 6, pl. 7, figs. 1 and 2, and pl. 8. 
No. 2453—PROCEEDINGS U. S. NATIONAL MUSEuM, VOL. 62, ART. 7. 
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