NO. 1401. GENERA OF SIMPLE FUNGID CORALS— VAUOHAN. 387 



1. Genus MICRABACIA Milne Edwards and Haime. 



1849. Mkrahacia, Milne Edwards and Haime, Comptes rend. Acad., Paris, 

 XXIX, p. 7. 



Genus placed by Milne Edwards and Haime in their Fung'mee^ 

 defined as having- " the plateau without epitheca, usually strong-ly 

 echinulate, tissues perforate.'" 



Original generic d'lagmmh. — " Septa moderately numerous antl 

 straight. Wall scarcely echinulate, costse alternating with the septa." 



Type species. — Fungia coromda Goldfuss, Petref. German., 1, p. 50, 

 pi. XIV, fig. 10; Micrahacia coronula., Milne Edwards, Hist. Nat. 

 Corall., in, p. 29. 



Distrihation. — Cretaceous, Craie tuffeau, Europe. 



He/narks. — Milne Edwards and Haime, in their Recherches sur les 

 Polypiers," elaborated their characterization of this genus, and Milne 

 Edwards gave additional detail in the third volume of the Histoire 

 Naturelle des Corallaires (p. 29). Duncan, in his Revision of the 

 Families and Genera of the Madreporaria,^ gives a still fuller 

 description, which 1 have ^•erified by a study of the type species. It 

 is as follows: '"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 depression, filled b}" a false 

 columella, from which the principal septa radiate, being joined with 

 those of the higher orders toward the circumference. Septa numer- 

 ous, solid, imperforate, arched above, with a perpendicular outer edge. 

 Costa? distinct on the base, Ijifurcating at the edge, a process from two 

 costffi 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 synapticula, which radiate from the base in discontinu- 

 ous lines, bounding canalicular spaces continuous below w ith the inter- 

 costal openings, and above with the interseptal loculi high up. Cost* 

 granular. Septa crenulate or minutel}^ denticulate." 



2. Genus DIAFUNGIA Duncan. 

 1884. IHafungia Duncan, Jour. Linn. Soc. London, Zool., X^'II, p. 417. 



Original generic diagnosis. — "Corallum discoid, free, without trace 

 of adhesion, not quite circular in outline, much broader than high. 

 Base with a triangular piece extending beyond the center, slightly 

 projecting downward, the rest of the coral grouping from its sides 

 and apex, so that there is an appearance of former fracture and subse- 

 quent mending. Calice uns3'nimetrical from the prolongation of the 

 larger septa of the primary piece beyond the center, and from the 



«Ann. Sci. Nat., 3d ser., Zool., XV, 1851, p. 88. 



6 Jour. Linn. Soc. London, Zool., XVIII, 1884, p. 143. 



