MADREPORARIA FUNGIDA. 



305 



while there are synapticula but no dissepiments. Anabacia is dis- 

 coid in form, and of small size, and its basal wall is wanting. 



Family 5. Piesioporitidce. — This family includes Fungida in which 

 the septa are trabeculate and the septa regularly porous, thus ap- 

 proaching the Madreporaria Perforata. When a wall is present, it 

 is imperforate. Synapticula are present, and dissepiments may or 

 may not exist. Most of the genera included in this family {Lepto- 



[85. — Cyclolites elliptica, viewed from above, rom below, and from the side. Cretaceous. 



phyllia, Cyclolites, Microsole?ia, &c.) are Jurassic or Cretaceous, the 

 well-known genus Cyclolites occurring in both of these formations. 

 In this genus (fig. 185), the corallum is simple and free, discoid, 

 with a flat or slightly concave base, and either circular or elliptical 

 in outline. The under surface of the corallum is covered with a 

 well - developed, concen- 

 trically striated basal plate. 

 The septa are trabecular 

 and more or less per- 

 forated, and there is either 

 no columella or a rudi- 

 mentary one. 



Forming a transition 

 between the typical Fun- 

 gida and the typical Perfo?'- 

 ata is the Jurassic genus 

 Microsolena (fig. 186), in 

 which the corallum is mas- 

 sive, of variable shape, but 

 usually more or less lobed. 

 The basal wall is covered 

 with a strong epitheca, and 

 the calices are not circumscribed by a definite wall. The septa are 

 trabecular and perforated, and synapticula are abundantly developed. 



vol. 1. u 



186. — Fragment of Microsoloia rantosa, and three 

 of the calices of the same enlarged. Jurassic. 



