100 allan hancock pacific expeditions vol. 14 



Key to Families 



1. Ovicells hyperstomial 2 



Ovicells endozooecial or wanting 3 



2. Ovicells very large, very prominent ; avicularia large, replacing 



zooecia ; opesiules closed Thalamoporellidae 



Ovicells normal in size and appearance; opesiules joining 

 the opesia (sometimes scarcely evident) ; avicularia smaller 

 (sometimes wanting) Aspidostomidae 



3. Zoarium discoidal, free, saucer-shaped or short conical; distal 



to each zooecium is an auriculate avicularium with long 



setose mandible Lunulariidae 



Zoarium encrusting; avicularia replacing zooecia 4 



4. Zooecia of two kinds, one with a much enlarged operculum ; 



polypide tube complete Steganoporellidae 



Zooecia of one kind ; avicularia various ; polypide tube incom- 

 plete Microporidae 



Family MicroporidaC Hincks, 1880 



There is much variation in the extent of the cryptocyst in this family 

 and the opesial area may be moderately large or nearly wanting except 

 for the opesiules, which may be separated from the opercular area (closed) 

 or united with it (open). Avicularia may be large or small, sometimes 

 with long slender mandibles which are winged on one or both sides at 

 the base (onychocellaria). The ooecium when present is endozooecial. 

 Key to Genera of Microporidae 



1. Avicularian mandible winged at the base (onychocellarium), 



subfamily Onychocellinae 2 



Avicularian mandible not winged, Subfamily Microporinae. , . 4 



2. Avicularian mandible falciform, asymmetrical with wing on one 



side Onychocella 



Avicularium sjonmetrical or wanting 3 



3. Opesiular notches very distinct, directed laterally. . . . Floridina 

 Opesiular notches shallower and directed more proximally. Velumella 



4. No avicularia ; opesiules long parallel slits Caleschara 



Avicularium small, distal to aperture; cryptocyst complete ex- 

 cept for the aperture and very small opesiules 5 



5. Encrusting, ovicells conspicuous but endozooecial. . . Micropora 

 Erect and branching, no ovicells Microporina 



Genus ONYCHOCELLA Jullien, 1882 



The cryptocyst is extensive, depressed, not differentiated from the oral 

 shelf and continued broadly around the distal border of the aperture; 

 opesia reduced to little more than the orifice, opesiules open, often in- 



