^3J^ K. NISHIW.A.DA: (»IKiAXIO REMAINS FROM THE 



opiiiifjii as to ideiitiücati<3n of the fossil species, in conformity with 

 Avhich he deseribed 14 s[>ecies. In the determination of tlie present 

 species I also am inchned to lolhnv Giindjeh 



Tile remains of our Lithodiaiiiiiloii play such an im[)ortant 

 rule in the l)uildin^- up of ihe limestone, as to warrant the de- 

 signation of J.ilJiotliaiiiiuoti-Liiiicsloitc (^Xiilliiion'Nlialh-). The frac- 

 tured surfaces have a porcellan<His aspect, and are cream-white 

 in colour. 



The thallus is nuich ramitied into tinv stalactic forms or 

 shrubs, Avhich are rounded at the ends, variable in length and breadth, 

 measuring from 1 to .') nun. across, and having smooth surfices. 

 (Fig. 1, PI. XXIX). Generally it i-esembles either that of L. 

 hi/ssoidcH (Lamarck) Phil., a hving species in the Adriati<; Sea, 

 which was d('scril)ed and figured by Dr. Ilauck in his ^lecroiühjcn 

 Dcutschlaiuls und ( fcslerrt'icJis.^ or (he lower <;)ne of the two fii^'ures 

 given in Prof. Zittel's llanihucli der ValaeutilLdnijic." 



I*]xamined under tlie microscope, tiie cells composing the 

 outer p>art of a bi'anfh of the thallus are G-8 angled (not unfre- 

 rpiently 5-7 angled according t(j the impei'fection of tlie slides), 

 as may be seen in a ti'ausverse section. A vertical section, on 

 the other hand, shows that the tissue-cells are mainlv of rectangular 

 shape and regularly arranged in layers lying one on anotlier as 

 concentric shells. In certain slides, sections of the cells show the 

 walls as either njund or sinuous ; they can then hardiv be dis- 

 tinguished {vom those seen in a tangential section of Solrmtpora^^ 



The cell-division is active. In the '' hvpothallium," so- 



1. Lijipziy:. 1S85, p. -llô, Tai. II.. Fig. l. 



2. IL Ahth. PahieopJii/tologif, Leipzig. 1890, p. 38. 



3. A. Nicholson^aud EtheriJgo, Geol. Mart , Dec. Ill, Vol. II, p. ö'^'J. 

 , Geol. MiKj. Dec. III., Vol. V., p. 15. 



A. Brown, „ „ Dec. IV., VoL I., p. 115 and 105. 



