194 



MARINE INVERTEBRATES 



opening of the cell has no operculum. Ovicells, containing the 

 embryos, appear like pear-shaped swellings, 



GENUS Crisia 



C. eburnea. This species is found in tide-pools on algae, especially 

 on the red seaweeds, growing in bushy tufts from one half of an inch to 

 an inch high. Calcareous, with horny joints; cells in 

 two rows, semi-altei-nate, cylindrical, free at one end, 

 bent ; no operculum ; ivory-white ; ovicells largo and 

 pear-shaped. Common from Long Island Sound north- 

 ward and on the Pacific coast. 



GENUS Tubulipora 



T. flabeUaris. This species is found attached to 

 slender branched algae, in coral-like masses of long, 

 crooked, tubular cells united at the base and spreading 

 into fan-shapes placed flat against the fronds. It is 

 sometimes one quarter of an inch in diameter. On the 

 same alga may often be found Crisia, Mollia, and Celle- 

 pora. (Plate XLIX.) 



GENUS IHastopora 



D. patinao Tubular cells rise from a saucer-shaped 

 disk about a quarter of an inch in diameter ; cells lie 

 obliquely or stand erect, and are crowded toward the 

 center; margin of disk without cells; colony white 



and calcareous. Found on algae and eel-grass from Long Island 



Sound northward. 



Crisia eburnea 

 branch bearing ovi- 

 cells, highly magni. 

 fled. 



SUBORDER CHEILOSTOMATA 



In this suborder the zocecia are either horny or calcareous, and 

 the orifices are usually surrounded with spines and have opercula. 

 The orifices generally have raised margins, or peristomes. Ovicells 

 form helmet-like coverings overhanging the orifices. 



GENUS JEtea 



JE. anguinea. Delicate, white, creeping, calcareous stems, from which 

 iise numerous club-shaped cells, about one eighth of an inch high, each 

 one with an aperture in the end. This species creeps in wavy lines 

 along the fronds of algae, and is frequently found on Dasya, Griffithsia, 

 Plocamium, and eel-grass. 



