

TABULATA FAVOSITIDAK 



sometimes tubiform iniir;il JMHVS. Tin 1 cnrallites BT6 u-iially polygonal in 

 contour, and their walls exhibit in t ran>\ crse sections a dark, or sometim.-s 

 lii^ht coloured median line, with thickenings of itereOpUtftma OD either >id> 



FIG. 174. 



G If. sp. Devonian ; EitVl. A, Corallum, natural si/.-. B, Gorallites enlarged, two 



of them brokrn opni and showing tabulae, ''and /', Trans\ ITS.- and longitudinal suctions sho-.vin;,' spiniform 

 srptu and mural pon-s(/i). (''and I> al'ti-r Nicholson.) 



17(. (/). The family is exclusively Palaeozoic, and plays an important part 

 in the formation of Silurian, Devonian, and Carboniferous coralline limestone.-. 



/'os//,. s Lam. (fW/fm'Y^/w, Goldf.), (Fig. 174). Corallum massive, more 

 rarely branching. Corallites prismatic, polygonal, 

 generally hexagonal. Mural pores distributed at 

 considerable intervals. Septa very faintly developed, 

 represented by longitudinal ridges or rows of spines, 

 or occasionally obsolete. Tabulae numerous. Ordo- 

 vician to Carboniferous: very abundant in Silurian 

 and Devonian. 



''iiliiinin./Hini, Nidi, (('tifiijiwiii. Bill.) Like the 

 preceding, but with numerous, short, well marked 

 septa. Mural pores large, disposed in vertical rows 

 between the >epta. ( )rdovieiaii. 



EmmotuiOy K. and II.; Ordovician to Carboniferous. 



A i/rfn/Hn-<i, Nidi. ; ( )rdo\ ician (Trenton). S-yringolites, 

 Hinde : Silurian (Niagara). 



Packypora, Lind. (Ki^. 17.")). Corallum branching, composed of prismatic, 

 polygonal corallitcs, the walls of which are so thickened towards their mouths 

 by layers of stereoplasma that the calices appear to have 

 circular coiit nrs. Septa very minute ; mural pores 

 scanty, but often of large size. Abundant in Silurian 

 and Devonian. 



Ti-tii-hi//Mn-ii. ]".. and H. Dendroid with cylindrical 

 stems. Corallites polygonal; walls so thickened by lavers 

 of stereoplasma that the calices become round and great Iv 

 contracted, and appear to be superficially widely separated. 

 Mural pores few and irregularly distributed. Septa represented by rows ( ,i 

 spines. Tabulae remote. Common in Devonian. 



Ki... 17'.. 



I'r.'cli 

 ; Kit-!. .!. , 



/:. Longitudinal 

 section, enlarged; i>, Mmal p.m-s 



(atVr Nicholson). 



Th, 17.'.. 



Silurian (Niagara); x.-v 



York. 



