GENUS SPHENODEEIA— SPHENODEEIA LENTA. 229 



constant associate of the common rotifer among mosses and other plan's 

 in damp, shaded places. I find it abundantly, all the year round, in the 

 crevices of the brick pavement, in front of my house, about the roots 

 of the little pearlwort, Sagina apetala. This small form appears to have a 

 homogeneous shell, and is about 0.0238 mm. long by 0.02 mm. broad. In 

 dry weather, like the rotifer, it becomes quiescent, but during and after 

 rain it assumes the active condition. 



SPHENODERIA. 



Greek, sphen, a wedge; dcra, the neck.* 



Shell globular or oval, sometimes slightly compressed, hyaline, mem- 

 branous, with a short, broad neck, and a wide elliptical, subterminal, or 

 oblique (?) mouth. Body of the shell with circular, oval, or hexagonal 

 cancelli or plates arranged in alternating series. Sarcode and pseudopods 



as in Euglypha. 



SPHENODERIA LENTA. 



Plate XXXIV, figs. 25-41. 



Splenoclcria lenta. Schlumberger : An. Sc. Nat. 1845,256.— Ehrenberg: Abh. Ak. Wis. Berlin, 1871, 236. 

 Euglypha globom. Carter : An. Mag. Nat. Hist. 1865, xv, 290, pi. xii, fig. 14. — Hertwig and Lesser : Arch. 



mik. Anat. 1874, x, Suppl. 129, Taf. iii, Fig. 7.— Scbulze : Ibidem, 1875, 102, Taf. v, Fig. 5, 6.— 



Leidy : Pr. Ac. Nat. Sc. 1874, 226 ; 1878, 172. 

 Difflugia lenta. Ehrenberg: Abh. Ak. Wis. Berlin, 1871, 246. 

 Assulina lenta. Ehrenberg: Ibidem. 



Animal comparatively small. Shell delicate, membranous, colorless, 

 transparent, globular, oval or oblong, of uniform transverse diameter or 

 sometimes slightly compressed, with a short, broad, compressed neck, 

 widening toward the narrow elliptical mouth, which is oblique or subter- 

 minal (?). Border of the mouth thin, delicate, entire. Body of the shell 

 composed of circular or oval plates overlapping at their contiguous borders 

 and arranged in alternating series, and apparently not extending into the 

 neck. Sarcode as in Euglypha and Trinema. 



Size. — Globose forms from 0.032 mm. long by 0.028 mm. broad to 0.05CJ 

 mm long by 052 mm. broad or to 0.056 mm. in diameter ; oval forms from 

 0.028 mm. long by 0.02 mm broad to 0.056 mm. long by 0.044 mm. broad. 



Locality. — Common in moist sphagnum in the cedar and other bogs of 

 New Jersey, Pennsylvania, Alabama, and Florida ; also in swanqjy locali- 

 ties at Fort Bridger, Wyoming Territory. 



" Agassiz : Nomenelator Zoologicus, has <?f?os, the skin ; but this I infer to be a mistake. 



