NO. 2032. ROTATORIA OF WASHINGTON AND VICINITY— EARRING. 397 



swim unless absolutely compelled to do so, clinging with the greatest 

 tenacity to the diatom-covering so abundant on this plant. It is 

 most difficult to isolate, partly on account of its extreme hyalinity; 

 as soon as disturbed it immediately wriggles back into the mud, and 

 the search has to begin all over again. It has not been possible to 

 preserve it in anything resembling its normal form. 



DIGLENA CLASTOPIS Gosse. 

 Plate 34, figs. 11-13. 



For some time this species was in doubt; the animal found here 

 does not have the remarkably long-stalked subcerebral glands figured 

 by de Beauchamp^ and the slender, L-shaped epipharyngeal rods are 

 not shown in his figm^e of the trophi.^ De Beauchamp was good 

 enough to send me some material for comparison, which demon- 

 strated that the two animals are alike in all respects, except that the 

 specimens from France have the subcerebral glands, readily seen 

 even in preserved material, while in the local form they are totally 

 absent. An exactly parallel case is cited by de Beauchamp (p. 158): 

 Specimens of Dicrmwphorus ( = EospJiora) auritus (Ehrenberg)^ 

 collected near Bourg (Ain), have long subcerebral glands, while 

 others from near Paris have extremely short glands. It seems pos- 

 sible that each of these two species may eventually prove divisible 

 into two vaHd subspecies; however, the discovery, or at least the 

 recognition, of the retrocerebral organ by de Beauchamp is of com- 

 paratively recent date and no information is as yet available con- 

 cerning the extent of its possible variation, so that it seems preferable 

 to consider these forms provisionally as belonging to a single species. 



LECANE STICH.S;A, new species. 

 Plate 35, figs. 4-6. 



In complete retraction the dorsal plate of the lorica is ovate; the 

 frontal edge curves slightly forward. For two-thirds of its length 

 the ventral plate is nearly parallel-sided, the posterior end being 

 rounded; it projects considerably beyond the dorsal plate and very 

 shghtly over the movable foot joint. At the anterior edge of the 

 lorica there are two conspicuous lateral points. The lateral sulci 

 are of moderate depth. Both dorsal and ventral plate are facetted 

 as shown in the figure. 



The first foot joint is hardly distinguishable, the second, or mova- 

 ble, joint is comparatively large and stout, somewhat enlarged pos- 

 teriorly and has a broadly heart-shaped emargination in front. The 

 toes are a Uttle less than half the length of the dorsal plate; in 

 dorsal view they are parallel-sided, in lateral view they taper notice- 



1 Arch. Zool. Exp., ser. 4, vol. 10, p. 157, fig. XD F. 

 2P. 227, fig. XXXV B. 



