NO. 1355. FRESH- WA TER BR YOZOA—DA VENPORT. 219 



LOPHOPUS CRISTALLINUS Pallas ( 1766). 



This species possesses the characters of the genus. 



ITnhitat. — Chie% standing water .such as pools or, rarely, .slow- 

 flowing streams. Chie% attached to plant stems. 



Dlstrihutlnn. — Europe; Schuylkill River near Philadelphia (Leid}-, 

 1858); Illinois River at Havana (Kofoid, 1898). 



PECTINATELLA Leidy. 



Colonies are hyaline and have the form of a rosette, lobed, with 

 horizontal tubes only. They secrete a great gelatinous base which is 

 common to many colonies. Aperture slightly elevated above conunon 

 ccenecium. Statoblasts large and circular to subrectangular, with 

 broad bent float and one marginal row of anchor-shaped hooks. 



PECTINATELLA MAGNIFICA Leidy (1851). 



Polypides scattered or in double row along each lobe, the gc^latinous 

 base often 1(» to 20 centimeters thick. Tentacles 60 to 84 in number. 

 Statoblasts about 1 mm. in diameter, provided with 11 to 22 hooks 

 from 0.15 to 0.25 mm. long. (Plate V, fig. 8.) 



Ilahitat. — Submerged branches or twigs of trees, wooden stakes, 

 gates of dams, walls of reservoirs, stones in brooks. Shad}^ situations, 

 such as south walls of reservoirs or wood-covered streams. 



BistributUm. — Conflned to North America, except as introduced at 

 Hamburg, Germany. * Jones's Pond, near West Gouldsboro, Maine 

 ("P. astr^eoidea, Hyatt," collected by Una A. Clark, 1897, in National 

 Museum, Ace. No. 32589; also in Boston Soc. Nat. Hi.st.); Pennis.se- 

 wassee Pond, Maine (20-22 hooks on statoblast); Fresh Pond, Cam- 

 bridge, Massachusetts (12-17), both by Hyatt; * walls of College 

 Hill reservoir, Somerville, Mas.sachu.setts; *Cold Spring Harbor, 

 Long Island, New York, gates of dam between middle and lowest lake; 

 Philadelphia (Leidy, 1851); Black Channel, Sandusky (Landacre, l!»Oi); 

 Jack.son Park Lagoon, Lake Michigan, at Chicago (C. B. D., 1900); 

 "back water'" of Mississippi bottoms near Quincy, Illinois (H. Gar- 

 man, 1888); Columbus, Mississippi (Leidy, 1858); * Squaw Bay, Put 

 in Bay, Lake Erie (August 16, 1898, Reighard); *IUinois River, near 

 Havana, from rocks and shells, "island" near old bridge, October 14, 

 1894 (Forbe.s); * Roadside Pond, in Hamilton County, Illinois (Octol)er 

 3, 1900, Forbes); * Little Muddy River, Franklin County, Illinois, 

 October 18, 1900 (Forbes). 



CRISTATELLA Cuvier. 



Colony unbranched, gelatinous, with a flat "".sole." External cuti- 

 cula lacking, or developed merely as a thin gelatinous layer under the 

 Proc. N. M. vol xxvii— 03 15 



