THE SUBDIVISIONS OF MONTICUIIPORA. 91 



genus the Prasopora of Mr R. Etheridge, jun., and myself, 

 while I shall institute a fifth sub-genus under the name of 

 Perofiopora. As the present work is concerned wholly with 

 the genus Monticiilipora proper, I shall here subjoin all remarks 

 which I find it necessary to make upon Fistulipora, Constel- 

 lari'a, and Dekayia, at the same time briefly defining JMonticit- 

 lipora and Its minor subdivisions. 



It being understood, then, as above stated, that the term 

 gams is here used in a purely artificial sense, I propose to 

 divide the family MonticuliporidcB into the following four 



genera : 



(I.) Fistulipora, M'Coy, 1849. 



(Ann. and Mag. Nat. Hist., ser. 2, vol. iii. p. 130.) 

 Callopora, Hall, Pal. N.Y., vol. ii. p. 144, 1852. 



The corals of this group were separated by M'Coy to form 

 his genus Fishdipora, with the following generic diagnosis : — 



" Corallum encrusting, composed of long, simple, cylindrical, 

 thick-walled tubes, the mouths of which open as simple, equal, 

 circular cells on the surface, and having transverse funnel- 

 shaped diaphragms at variable distances ; interval between 

 the tubes occupied by a cellular network of small vesicular 

 plates." The type of the genus is the F. minor, M'Coy, of 

 the Carboniferous Limestone of Derbyshire. 



At a later period. Professor Hall proposed the name of 

 Callopora for certain Upper Silurian corals, with the following 

 eeneric cliao-nosis : — 



" Ramose or encrusting species of corals, having a columnar 

 structure ; cells tubular, with the apertures circular or petalold, 

 not contiguous, and having the intermediate spaces occupied 

 by angular cell-like openings which are transversely septate ; 

 tubular cells rarely septate." ^ 



' The term " septate," used by Professor Hall in the above diagnosis, is employed 

 in the same sense as " iabulatcl' and does not refer to the presence of true septa. 



