FAMILIES AND GEI^EEA OF THE MADEEPOEAEIA. 



143 



costal spaces regularly furnished with equidistanfc synapticula, 

 presenting a regularly perforated appearance. Synapticula 

 strongly developed between the septa, some reaching high up iu 

 the interseptal loculi. There is no true wall, the septo-costal 

 structure being united by synapticula alone. 

 Distribution. — Becent. Korean Sea. 



Were there symmetrical growth, and did the costse radiate 

 from a common centre, the form would come within the genus 

 Micrahacia (Edwards and Haime, Hist. Nat. des Corall. vol. iii. 

 p. 30, 1860). The genus is therefore a very interesting addition 

 to the family Eungidse, and must be placed between the genera 

 Fungia and Micrahacia. 



It is mimetic of the genus Diaseris of the Lophoserinse. 



The genus Micrahacia, Milne-Edwards & Jules Haime, requires 

 some amendment , and having had the opportunity of studying 

 some good specimens, I give the following amended diagnosis : — 



Grenus Micrabacia, Milne-Edwards <Sf Jules Haime, Hist. Nat. 

 Corall. vol. iii. p. 29 (1860), amended. 



Corallum simple, free, lenticular, broader than high, convex 

 above, slightly concave at the base, which has a circular out- 

 line. Calice with a small shallow axial depressiou, filled by a 

 false columella, from which the principal septa radiate, being 

 joined with those of higher orders towards the circumference. 

 Septa numerous, solid, imperforate, arched above, with a perpen- 

 dicular outer edge. Costse distinct on the base, bifurcating at 

 the edge, a process from two costsD forming a septum. Intercostal 

 spaces continuous with the line of direction of the septa, crossed 

 by synapticula in concentric rows, and perforate between the 

 synapticula. Interseptal loculi crossed by large and small synap- 

 ticula, which radiate from the base in discontinuous lines, bound- 

 ing canalicular spaces continuous below with the intercostal 

 openings, and above with the interseptal loculi high up. Costge 

 granular. Septa crenulate or minutely denticulate. 



Distrihution. — Fossil. Cretaceous : England, Europe. 



n. AlHance CRYPTABACIOIDA. 



Colonial Fungidse. Calices all distinctly radiating. 



Genus Halomitra, Dana. 

 Genus Sandalolitha, Quelch. 

 Genus Cryptabacia, Ed. & H. 



