164 INVERTEBRATE ZOOLOGY 



Molluscoidea. Both mouth and anus occur on the extremity 

 bearing the lophophore. The larva, which is known as actino- 

 trocha, is a modified trochophore. 



Outline of Classification 



Phylum MoUuscoidea.^ — Triploblastic; aquatic; lophophore bearing ciUated 

 tentacles; anus near anterior end. 



I. Class Polyzoa. — Zooids small; usually colonial; alimentary canal 

 U-shaped. 



1. Order Ectoprocta.- — Anus outside lophophore; coelomate. 



a. Suborder Gymnolaemata. — Lophophore circular; chiefly 

 marine. Crisia, Stenopora, Bugula, Membranipora, Paludicella, 

 Tubulipora. 



b. Suborder Phylactolaemata.^ — Lophophore horseshoe- 

 shaped; fresh water. PlumateUa, Fredericella, Pedinatella, 

 CristateUa. 



2. Order Endoprocta. — Anus within lophophore; no coelom. 

 Loxosoma, PediccUina, UrnateUa. 



II. Class Brachiopoda. — Bivalve shell; marine; solitary; usually a 

 peduncle for attachment. 



1. Order Inarticulata. — Valves of shell without hinge; shell 

 chiefly organic; anus present. Lingula, Crania, Discina, Glotiidia. 



2. Order Articulata. — Valves of shell hinged; shell limy; no anus. 

 Terebr alula, Waldheimia, Magellania, Laqueus. 



III. Class Phoronida. — Marine; wormlike; in cylindrical sand tube. 

 Phoronis. 



References 



(See general references cited at the close of Chapter I) 



Allmann, G. J. 1856. "Monograph of the Fresh-water Polyzoa." 

 London. Ray Society. 



Davenport, C. B. 1890. CristateUa: The Origin and Development of the 

 Individual in the Colony. Bull. Mus. Comp. Zool, Harvard, 20: 

 101-152. 



■ . 1893. On Urnatella gracilis. Bull. Mus. Comp. Zool, Har- 

 vard, 24: 1-44. 



Morse, E. S. 1902. Observations on Living Brachiopods. Mem. 

 Boston Soc. Nat. His., 5. 



Osburn, R. C. 1910. The Bryozoa of the Woods Hole Region. U. S. 

 Bur. Fish. Bull, 30: 203-266. 



