GENUS CYPHODEHIA. 201 



Both have ovoid shells, in one incorporated with diatoms, in the other with 

 sand and of a yellow color. Schulze admits these as species, and describes 

 others he regards as the same,* but I would regard all as varieties of 

 Pseudodifflugia gracilis. 



The latter author has described two other forms with the names of 

 Pleuroplirys compressa and P. lageniformis, but these also I incline to believe 

 belong to the Pseudodifflugia gracilis as mere varieties. 



Hertwig and Lesserf have described a rhizopod which they regard as 

 Pleuroplirys sphcerica, to which they also consider the large form pertains 

 described by Mr. Archer. The specimens indicated by the former have an 

 ovoid, brown, granular shell, ranging from 0.03 mm. to 0.05 mm. In struc- 

 ture, form, and size they sufficiently accord with Schlumberger's description 

 to belong to Pseudodifflugia gracilis. 



Quite recently, since the present work went to press, Mereschkowskyl 

 has described a form under the name of Pleurophrys angulata, which ap- 

 pears to me not to differ from the former. 



Fig. 28, pi. XXXIII, represents a remarkable variety obtained from 

 ooze in a lake of the Uinta Mountains, Wyoming Territory, but the only 

 specimen of the kind seen, though ordinary forms were common enough. 

 The shell was amphora-shaped, with a nipple-like process to the fundus 

 and a rim to the mouth, and was composed of comparatively coarse sand 

 grains. Its length was 0.06 mm. ; its breadth 0.036 mm. The pseudopods 

 extended in a dense bundle. As a conspicuous variety, this might be 

 appropriately distinguished as Pseudodifflugia amphora. 



CYPHODERIA. 



Greek, kuphos, curved; deros, the neck. 



Difflugia : Ehrenberg, 1840. Cyphoderia: Schluinberger, 1845. Eughjpha: Perty, 1852. Lagynis : Schultze, 

 1854. Ampullaria; Hologlyplia; Assnlina: Ehrenberg, 1871. 



Animal provided with a retort-shaped shell, the mouth directed down- 

 ward, and the long axis of the body inclined. Structure of the shell 

 chitinoid, transparent, colored or colorless, composed of minute hexagonal 

 elements of uniform size arranged in alternating series in parallel spiral 

 rows. Mouth minutely beaded. Sarcode pale, granular, usually nearly 



*Archiv mik. Anatomie, 1875, xi, 122. 



t Archiv mik. Anatomie, 1874, 135, Taf. iii, Fig. 4. 



t Ibidem, 192, Taf. x, Fig. 14. 



