106 FEESH-WATEE EHIZOPODS OF NOETH AMEEICA. 



DIFFLUGIA URCEOLATA. 



Plates XIV; XVI, figs. 32-34; XIX, figs. 28, 29. 



Difflugia urceolaia. Carter : An. Mag. Nat. Hist, xiii, 1864, 27, 37, pi. i, fig. 7.— Leidy : Pr. Ac. Nat. So. 



1877, 307. 

 Difflugia lageniformis. Wallich: An. Mag. Nat. Hist, xiii, 1864, 240, pi. xvi, figs. 15, 16.— Leidy: Pr. Ac. 



Nat. Sc. 1874, 14. 

 Difflugia proteiformis, subspecies D. rnitrifomiis, var. D. lageniformis. Wallich : Ibid. 

 Difflugia amphora. Leidy : Proc. Ac. Nat. Sc. 1874, 79. 

 Difflugia olla. Leidy: Proc. Ac. Nat. Sc. 1874, 156; 1877,307. 



Shell amphora-form ; body spheroid, ovoid, or ovate, with the fundus 

 obtusely and evenly rounded, or more or less acute, or acuminate, and 

 rarely furnished with several usually blunt spines ; neck short, more or less 

 contracted ; mouth large, circular, terminal, with or without a rim of varia- 

 ble breadth, usually reflected and terminating in a thin delicate edge. Struc- 

 ture of the shell commonly of hyaline quartz-sand ; rarely of chitinoid 

 membrane with variable proportions of diatoms and sand. Sarcode color- 

 less ; pseudopods many, digitate, simple, and branching. 



Size. — Of the spheroid forms, from 0.18 mm. to 0.44 mm. long by 0.14 

 mm. to 0.38 mm. broad; of the ovoid forms, 0.2 mm. to 0.52 mm. long by 

 0.14 mm. to 0.36 mm. broad. 



Locality. — Ditches and ponds in the vicinity of Philadelphia ; ponds of 

 sphagnous swamps in New Jersey ; pools and ponds at Fort Bridger, on 

 Bridger Butte, and in the Uinta Mountains, to an elevation of 10,000 

 feet, Wyoming Territory. 



Difflugia urceolata was originally described by Mr. Carter from 

 specimens found in England. It is represented as of oval form, slightly 

 prolonged to form a short neck, and with a rim slightly reflected. Its size 

 is stated at ±d of an inch in length and id of an inch in breadth. 



The species was described the same year by Dr. Wallich, likewise from 

 specimens found in England, under the name of Difflugia lageniformis. It 

 is represented of oval form, with a short contracted neck and a strongly 

 reflected lip. 



Difflugia urceolata is the largest species of the genus, and is common in 

 the ooze of ditches traversing the meadows below the city of Philadelphia, 

 and communicating with the Delaware and Schuylkill Rivers. It is also 

 frequent in the ponds of sphagnous swamps, such as those of Atco, and 



