EARLY TERTIARY CHEILOSTOME BRYOZOA. 27 



larium is narrow, fusiform, somewhat larger than the zocecia; the 

 opesium is median, oval, the point below, with a narrow and den- 

 ticulated posterior; the terminal point projects above the distal 

 zocecium, but is very fragile; the distal canal through alteration in 

 fossilization fuses nearly always with the cryptocyst of the distal 

 zocecium. The heteromorphic zocecia are a little smaller ; their cryp- 

 tocyst is longer than the opesium which then appears nearly trans- 

 verse. The ancestrula is of the same form as the zooecium. 



Measureinents. — Opesium of 



Zocecium 



Opesium of onychocellaria 



A(9=0.20 mm. (measuring only to 

 the polypidian convexity). 

 zocecia ] Zc»=0.15 mm. (without the oj^esi- 

 ules). 



Z2=0.40 mm. 



7,2=0.30 mm. 



^071=0.20 mm. 



Zo/>?t=0.10 mm. 



^ , ,, . f Z«9?i= 0.40-0.45 mm. 

 Onychocellaria j^^^^Q 20 mm. 



Occurrence. — Middle Jacksonian: Wilmington, North Carolina 

 (common). 



Upper Jacksonian (Ocala limestone) : Old Factory, 1^ miles 

 above Bainbridge, Georgia (common). 



Vicksburgian : Salt Mountain, 5 miles south of Jackson, Alabama 

 (rare). 



Type.—Q'^t. No. 62582, U.S.N.M. 



Subfamily Microporidae, Hincks, 1880. 



The ovicell is endozocecial. The parietal muscles, attached at the 

 ectocyst, pass through the calcareous cryptocyst, either by the opesiu- 

 lar indentations or by true perforations called opesiules. The semi- 

 circular aperture has generally a more or less strongly chitinized (or 

 calcareous) simple operculum, more seldom an oj)ercular valve. 

 Avicularia present. 

 The genera comprising this subfamily are : 



Rosseliarui Jullien, 1888. Eocene-Recent. 



Floridinella^ new genus. Vicksburgian. 



Gargantua Jullien, 1888. Miocene-Recent. 



Dacryonella^ new genus. Jacksonian. 



Aechmella, new genus. Cenomanian-Miocene. 



Micro'pora Gray, 1848. Midwayan-Recent. 



