NO. 3 OSBURN : EASTERN PACIFIC BRYOZOA CYCLOSTOMATA 759 



Phylum Entoprogta 



By Raymond C. Osburn, Ph.D., D.Sc. 



Phylum ENTOPROGTA Nitsche, 1869 



Subphylum Entoprocta, various authors. 

 Phylum Entoprocta, Hatschek, 1888. 

 Phylum Calyssozoa Clark, 1921 : 19 and 23. 

 Phylum Kamptozoa Cori, 1929:5. 

 Phylum Entoprocta, Hyman, 1951:521. 



Until recent years this group has generally been considered a sub- 

 phylum or subclass of the Bryozoa, although Hatschek as early as 1888 

 (Text-book of Zoology) separated the Phylum Entoprocta. In 1921 

 Clark recognized the differences and proposed the Phylum Calyssozoa. 

 Again Cori in 1929, though he was familiar with the name Clark had 

 suggested, thought it necessary to rename the group as Phylum Kamp- 

 tozoa. These writers considered the Entoprocta to be much simpler than 

 the Ectoprocta and separated them widely. Marcus (1939:208-288) 

 raised objections to this wide separation and gave some very cogent rea- 

 sons for retaining the group as a subphylum of the Bryozoa. Recently 

 Dr. Libbie Hyman, in the third volume of "The Invertebrates" (1951 : 

 521-554) again separates the group as a phylum. She assigns it to a 

 place much lower in the scale and retains the name Entoprocta for the 

 very good reason that it is unnecessary to invent a new name when a 

 perfectly good one already exists. Hyman's discussion is a very satisfac- 

 tory analysis of the knowledge of the Entoprocta, and it seems unneces- 

 sary to argue the matter further at present. 



Whether or not the entoprocts are closely allied to the ectoprocts and 

 wherever they may eventually be placed in the taxonomic scale, it hap- 

 pens that the only taxonomists who have paid much attention to them 

 are the bryozoologists, and for this reason the species which are known 

 from the Pacific coast are appended to the Bryozoa. The list is small 

 as the species are not numerous, and the littoral species are rarely found 

 among the dredgings. 



The Entoprocta are stalked, with naked heads or calyces (polypides), 

 the tentacles rolled inward instead of being withdrawn into a zooecium, 

 and the anal opening is within the ring of tentacles instead of outside 

 as it is in the Ectoprocta. 



The family Loxosomatidae is unique in that the individuals live singly 

 and do not form colonies, and they live as epizoites on other animals, 

 usually on sponges, worms, other Bryozoans, etc. The only other family, 

 Pedicellinidae, is colonial and is represented among our material by 4 

 genera and 8 species. 



