﻿GEOLOGY AND PALEONTOLOGY OF THE CANAL ZONE. 11 



ment of the living East Indian Lithothmnniuin pulchrum A. Weber 

 and Foslie.^ 



Lithothammuni fosUei (Trabucco) De Toni (Syll. Alg., vol. 4, p. 

 1761, 1905), a Miocene fossil from Italy, is figured* as having a 

 " coaxial " hypothallium, but from the illustrations given of the con- 

 ceptaeles, there is no sufficient ground for considering this plant 

 to be a Lithothamnium, rather than a Lithophyllum. In the original 

 place of publication nothing but a figure (section) is given, from 

 which, according to the scale of magnification given, it would appear 

 that the conceptacles are only 140-160 [x by 80-90 [jl and the perithallic 

 cells about 16 pi high, making the cells rather larger and the con- 

 ceptacles much smaller than in L. isthmi. 



If we are correct in including with LithothaTrwbium isthmi the more 

 ramified forms collected by MacDonald and Vaughan, the species, 

 though commonly coarser, appears to be sometimes suggestive of 

 plants figured as NulUpora raniosissima Reuss or LithotJiammuTn 

 rcmiosissimmn (Reuss) Schimper, from the Tertiary " LeithaJealk " 

 of the vicinity of Vienna, but Reuss's original figures and descrip- 

 tion^ relate to external form only, and give no adequate basis for 

 referring the plant to a modern genus. Unger * adds good figures 

 of the vegetative structure, but shows no conceptacles. Rothpletz ^ 

 describes the conceptacles of L. ramosissimum as 280 p^. high, while 

 the height of the conceptacles of L. isthmi is 130-165 [x and the width 

 240-550 [X. Rothpletz has no doubt that there are two species of 

 Lithothamnieae in the " Leithakalk," which maj'- have been confused. 



UTHOPOUELLA MELOBESOIDES (Foslie) Foslie. 



Ldthoporella melobesioidcs (Foslie) Foslie, Kgl. Novske Videusk. Selsk., 



1909, pt. 2, p. 50. 

 Mastophora meiohcsioidcs Fosi-te, Kgl. Norsk© Vidensk. Selsk. Aarsber., 



3902. p. 24, 1903. 



Locality and geologic occurrence. — Tliis species occurs in small 

 quantity with Lithothammum isthmi in Emperador limestone of the 

 Oligocene age, "above foraminiferous marl at Agua Salud Bridge 

 about I mile north of New Frijoles on relocated line, Panama Rail- 

 road," D. F. MacDonald and T. W. Vaughan, 1911, Station No. 6024&. 



EXPLANATION OF PLATES. 



Plate 1. 



Archaeolithothanmium episporum M. A. Howe. 



Photograph, natural size, of the type-specimeus, collected at Point Toro, near 



CJolon, Panama Canal Zone, .January 10, 1910 (Howe 6832). The technical 



» Compare pi. 4. Siboga Bxped. Monog. 61. 



' Bulithothamiiium fosUei, Trab. Boll. Soc. Geol. Ital.. vol. 19, pi. 11, flg. 10, 1900. 

 •Haldlnger, Naturw. Abh., vol. 2, pt. 1, p. 29, pi. 3, figs. 10, 11, 1848. Type from 

 Neudorfl," Hungary. 



* Denkschr. k. Aka<3. Wiss. Wien, vol. 14, p. 23, pi. B, flgB. 18-22, 1858. 

 'Zeits. Deuts. Gcol. Ges., vol. 43, p. 320, 1891. 



8370°— 18h— Bull. 103 2 



