122 PROCEEDINGS OF THE ACADEMY OF [1887. 



NOTES ON FRESH- WATER RHIZOPODS OF SWATOW, CHINA. 

 BY ADELE M. FIELDE. 



During the month of February, in ooze taken from the pools and 

 ditches near my house, and preserved in soup-plates under water an 

 inch in depth, I have seen Amoeba radlosa, Amoeba verrucosa, 

 Dlfflugia pyriformis, Difflugia acuminata, Difflugia cornuta, 

 Difiugia corona, Difflugia nodosa, Diffiiigia eompressa, Difflugia 

 spiralis, Difflugia lobostoma, Difflugia globulosa, Arcella vul- 

 garis, Arcella discoides, Centrop)yxis aculeata, Centropyxis ecornis, 

 with the empty shells of Euglypha aiveolata, and the Heliozoans, 

 Actinophyrs sol, Actinophyrs picta, Actinosphcerium, and Acantho- 

 cystis. Of Difflugia spiralis, the greater number had shells 

 formed of vermicular pellets. In Difflugia lobostoma the mouth of 

 several specimens seen, was six lobed, and the shell of a glossy brown, 

 ovoid or spherical, and so constructed of oval plates mingled with 

 sand grains as to resemble Nebela. I have also seen several empty 

 shells of Difflugia cratera, of bright brown membrane, and of the 

 shape shown in Fig. 20, Plate XII, in Leidy's work on Rhizopods. 

 These shells were only xoVo of an inch in length, and had no sand 

 grains adherent. 



All the above species and varieties having been fully described 

 and illustrated by Leidy, in his book on the Fresh-water Rhizopods 

 of North America, I note their presence here only in order to record 

 the interesting fact of their wide distribution. 



In addition to the above, I have found another species, not de- 

 scribed by Leidy, which has been identified with Difflugia tri- 

 angulata, Lang, (Difflugia bipes, Carter). From the cancellated 

 character of the shell this form probably belongs to the genus 

 Nebela, Leidy. Another species observed is probably the Nebela 

 collaris, Leidy. 



The specimens of the form regarded as Difflugia (Nebela) 

 triangulata vary but little in size in a great number of specimens 

 observed, averaging ^^^y of an inch in length, with a mouth ^wo of an 

 inch in diameter ; with two horns on the lateral borders of the 

 fundus, the horns being usually joks of an inch in length, and 

 placed in different specimens at very different angles to the 

 long axis of the shell. In some specimens a protuberance rises 

 midway between the horns. The greatest diameter of the shells 



