220 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxvii. 



sole. All polypides contract into a common cavity. Statoblast large, 

 circular, with float and a circlet of hooks on both sides. 



Habitat. — In standing or slow-flowing water, on submerged branches 

 of dead trees, underside of lily pads, and on other aquatic plants. 



CRISTATELLA MUCEDO. 



Young corm of circular form, later elongated, worm-like, attaining 

 a length of 2 to 5 cm. in summer, to 28 cm. in autumn. Colonies often 

 gregarious in a common gelatinous substance. Eighty to 90 tentacles. 

 Statoblasts with 10 to 34 dorsal hooks, 20 to 50 ventral hooks. (Plate V, 

 fig. 9.) 



Var. o', genuina {= C. qphideaHyatt, 1868).^ — Statoblasts less than 1 

 mm. in diameter; hooks on dorsal side 10 to 22; on ventral side 20 to 3Y. 



Distribution.: — Europe; Pennissewassee Pond, Maine (Hyatt, 1868); 

 * Fresh Pond, Falmouth, Massachusetts (C. B. D., 1889); * Trinity 

 Lake, Pound Ridge, New York (C. B. D., August, 1889); * Union 

 Lake, Illinois River, Havana, Illinois, May 12, 1891; *Long Point, 

 Canada (Reighard, August 21 and 21, 1899) ; Station E, Illinois River, 

 Havana, Illinois, September 2, 1890. 



Var. /?, idoi (= C. ido) Leidy, 1858; C. lacustris Potts, 1881). — Stato- 

 blasts over 1 mm. ; hooks on dorsal side 20-34; on ventral side 38-50. 



Distribution. — Lily Pond, Newport, Rhode Island (Leidy, 1858; 



C. B. D., 1890); Harvey's Lake, Luzerne County, Pennsylvania (Potts, 



1884). 



AUTHORITIES CITED. 



1843. Allman, J. Synopsis of the Genera and Species of Zoophytes Inhabiting the 

 Fresh AVaters of Ireland. Report British Assoc. Adv. Sci. for 1843. 



1856. A Monograph of the Fresh-water Polyzoa. London. 



1880. AsPER, G. Beitrtige zur Kenntnis der Tiefseefauna der Schweizer Seen. 

 Zool. Anzeiger, III, pp. 200-207. 



1878. Cruger, K. The Largest of All Fresh-water Polyzoa. American Naturalist, 

 XII, p. 252. 



1890. Davenport, C. B. Cristatella: The Origin and Development of the Individ- 

 ual in the Colony. Bull. Mus. Comp. Zool., Harvard College, XX, pp. 101-152. 



1891. Budding in Paludicella and other Bryozoa. Bull. Mus. Comp. Zool., 



Harvard College, XXII, pp. 1-114. 



1888. Garman H. a Preliminary Report on the Animals of the Mississippi Bot- 

 toms near Quincy, Illinois, in August, 1888. Part I, Bulletin Illinois State Lab. 

 Nat. Hist., Ill, 123-184. 



1839. Gervais, N. P. Observations pour servir a I'histoire naturelle des Polypes 

 d'eau douce. Ann. fran^aise et etrangere d'anatomie et de physiologie. III, 

 pp. 129-176. 



1848. Beneden, J. B. van. Recherches sur les Bryozoaires fluviatiles de Belgique. 

 Nouv. Mem. de I'Acad. de Belg., XXI. 



1777. Blumenbach, J. F. Gottinger Magazine, I, p. 117. 



1866-68. Hyatt, A. Observations on Polyzoa, Suborder Phylactola^mata. Com- 

 munications Essex Institute, IV, pp. 167-228; V, pp. 97-112, 145-160, 193-232. 



1898. KoFoiD, C. A. The Fresh-water Biological Stations of America. Amer. 

 Naturalist, XXXII, pp. 391-406. 



