PONT1GULASIA. Oi) 



constriction of the neck situated a little distance above 

 the mouth, and the possession of an internal transverse 

 loop, or diaphragm, extending from side to side co- 

 extensively with the constriction, and of the same sub- 

 stance as the test, or adhering all round its sides, and 

 perforated for the emission of the pseudopodia. 



The organism named and figured by Leidy, first as 

 Difflugia ras, and afterwards as D. pyrifurmis var. vas 

 (Pontigulasia spectabilis Penard), may be taken as 

 typical of the genus. It was, in fact, created to receive 

 that particular form, but others have since been added. 



1. Pontigulasia vas (Leidy) Schouteden.* 

 (Plate XXIII, fig. 1 ; and figs. 70 and 71 in text.) 



Difflugia vas LEIDY in Proc. Acad. Philad. 1874, p. 155; 



and op. cit. 1875, p. 307 ; CERTES in Mission scient. Cap. 



Horn, VI (1889), Zool. 3, p. 13; CASH in Tr. Manch. 



Micr. Soc. 1891 (1892), p. 48. 

 Difflugia pyriformis var. vas LEIDY Freshw. Rhiz. N. Amer. 



(1879), pp. 99, 101, t. xii, ff. 2-9; HITCHCOCK Synops. 



Freshw. Rhiz. (1881), p. 12; PENARD in Mem. Soc. Geneve, 



XXXI (1890), 2, p. 137, t. iii, ff. 39-41; and in Rev. 



Suisse Zool. VII, 1 (1899), t. ii, f. 9; SCHAUDINN in- 



Deutsch-Ost- Africa, IV, 2 (1897), 19, p. 9; AvERiNTZEvin 



Ber. Siisswass. Nat. Ges. St. Petersb. I (1901), p. 212; 



LAGERHEIM in Forh. Geol. Foren. Stockholm, XXIII, 6 



(1901), p. 503; G. S. WEST in Jrn. Linn. Soc., Zool. 



XXVIII (1901), p. 318; THIEBAUD & FAVRE in Ann. 



Biol. Lacustre, I, 1 (1906), pp. 76, 79. 

 Difflugia pyriformis LEIDY (pars), Freshw. Rhiz. N. Amer. 



(1879), p. 102, t. xix, ff. 24-26. 

 Pontigulasia spectabilis PENARD Faune Rhiz. Leman (1902), 



p. 318, ff. 1-9 (p. 319) ; AVERINTZEV in Trudui S.-Peterb. 



Obshch. XXXVI (1906), 2, p. 167. 

 Pontigulawa vas SCHOUTEDEN in Ann. Biol. Lacustre, I, 3 



(1906), p. 338 (note). 



Test in lateral view round or ovoid, not compressed, 

 the constriction deep and well-marked, sometimes forti- 

 fied by comparatively large quartz-grains; the neck 



* [Pontigulasia spectabilis Penard : CASH, MS.] 



