218 PROCEEDINGS OF THE NATIONAL MUSEUM. 



Var. p, ojppressa. — Tubes repent, branching or thickly intertwined, 

 covering- the substratum. Few or no vertical branches. Cuticula 

 lightly colored to transparent. 



Var, y, cse,»pitom. — Tubes repent, with many elongated and ])ranched 

 vertical rami. Cuticula semiopaque, no evident keel. 



* Station E (main river) Illinois River, Havana, Illinois, September 

 10, 1894; * Calumet River, South Chicago, August 10, 1881 (Forbes). 



Yar. S^ fungosa. — Tubes repent. Vertical branches close together, 

 even fused, forming great solid masses. Cuticula brown; aperture 

 hyaline, slightly elongated. 



Pennisewassee Pond in Norway, Gorham, Great Falls, outlet of 

 Great Pond on Cape Elizabeth, Presumpscot River, all in Maine; 

 Fresh Pond, Cambridge, Mystic Pond, Arlington, Green River, all in 

 Massachusetts (Hyatt); *Pa3^son Park, Belmont, Massachusetts, June, 

 1890 (C. B. D.), growing profuselj^ on north side of stone wall; Lily 

 Lake, Mississippi River bottoms near Quincy, Illinois (Garman, 1888). 



PLUMATELLA PUNCTATA Hancock. 



PlumatcUu vesicidarls Leidy, 1854. 

 Plumatella vitrea Hyatt (1868). 



Horizontal branches only. Cuticula delicate, colorless, hyaline. 

 Elevated mouth cone, wrinkled and bospeckled with white. Found 

 in Europe and North America. 



Var. «r, prostrata. — Stock repent and open, forming long h3^aline 

 tubes that give rise to only a few, likewise repent lateral tubes. 

 (Plate V, fig. 7.) 



Sebago Lake, Maine (Hyatt); Mystic and Fresh ponds near Cam- 

 bridge (Hyatt, 18()8); Schuylkill River, underside of flat stones 

 (Leidy, 1854); Libby Lake, Mississippi River bottoms near Quincy, 

 Illinois (H. Garman, 1888); *East end Gibraltar, Put-in Ba}-, August 

 15, 1898; *Long Point, Canada, August 21,24, 1898. 



Var. /?, densii. — Stock repent, ver}^ thickly liranched, completely 

 covering the substratum, which seems enveloped in a thick layer of 

 gelatinous vesicles. 



LOPHOPUS Duniortier. 



Colony shaped like a sack; erect, sometimes more or less lobed by 

 indentations of margin, looking then something like a glove. Outer 

 cuticula layer delicate and hyaline, more incrusted at base. Polypides 

 scattered, a group of them rising from each lobe. Lophophors with 

 about 60 tentacles. Statoblasts large, elliptical, but at each end drawn 

 out into a sharp apex; float broad, hooks absent. The colon}^ may 

 divide along the constrictions between the lobes. 



