260 BRTOZOA 



lowish in color; zoa?cia hexagonal, closely packed together: from the Arctic 

 Ocean south to Long Island Sound, on stones, piles, crabs, etc., from tide 

 lines to deep water; Europe. 



A. hirsutum (Fleming) (Fig. 424). Colony incrusting or erect, com- 

 pressed, expanded, and branched, yellowish-brown or reddish in color, 

 the surface covered with conical papilla, between which are the orifices: 

 Long Island Sound to Arctic Ocean in shallow water, incrusting the 

 stems of fucus and other plants; common; Europe. 



Family 2. FLUSTEELLIDAE. 



Colony similar to the above, but the opening is bilabiate, with a 

 movable lip which acts as an operculum; lai-va (Cyphonautes) with a 

 bivalve shell: 1 genus. 



Flustrella Gray. With the characters of the family : 3 species. 



F. hispida (Fabricius) (Fig. 425). Colony a thick, brown crust, 

 roughened by numerous reddish spines.; zooecium ovate or hexagonal, with 



Fig. 425 Fig. 426 



Fig. 424 — Alcyonidium hirsutum (Osburn). Fig. 425 — Flustrella hispida (Osburn). 

 Fig. 426 — Bowerhankia gracilis (Osburn). 



a raised opening around which are one or more tall, red spines, which may 

 also be present along the margin of the cells: circumpolar, south 'to 

 Long Island Sound and Alaska, incrustmg the stems of fucus, etc.; 

 common; Europe. 



Family 3. VESICULARIIDAE. 



Colony horn-like or membranous, branching, and either erect or recum- 

 bent, the zocecia contracted below, budding off from a distinct stem: 

 5 genera. 



1. BowERBANKiA Farre. Colony recumbent; zooecia cylindrical, in 

 clusters often spirally arranged; 8 to 10 tentacles in a circle; gizzard 

 present between stomach and oesophagus: 20 species. 



B. gracilis Leidy (Fig. 426). Colony creeping, the cylindrical zooids 

 rising separately from the recumbent stem: coast of New England, on 

 iiydroids, seaweed, etc. 



2. Amathia Lamouroux. Colony erect; zooids in a double series: 

 several species. 



