THE MICROSCOPE. 



Vol. V. ANN ARBOR, JULY, 1885. No. 7. 



ORIGINAL COMMUNICATIONS. 



VOETICELLA LIMNETIS (Species nova). 



BY DR. ALFRED C. STOKES. 



THE following description of a previously unobserved form of 

 Vorticella relates to a species obtained in some abundance 

 on Utricularia from the cedar swamps of the New Jersey pine 

 barrens, where the water is so richly colored by the so-called 

 humic acid that the observer is led to expect that the micro- 

 scopic inhabitants will be equally well tinted. But such is not 

 the case. The Choano-Flagellata retain their distinctive green- 

 ish hue, Infusoria common also in other localities possess their 

 ordinary coloration, and the Vorticella here referred to has the 

 usual pale or colorless aspect of the group. This is an interest- 

 ing and suggestive fact. 



The present form is remarkable for the peculiar twisted ap- 

 pearance of the sheath of the pedicle, a characteristic which it 

 has in common with V. octava, described by the writer in " The 

 Annals and Magazine of Natural History " for June, 1885. But 

 aside from another and more valuable specific character, that 

 of its smooth cuticular surface, it is easily distinguished from 

 V. octava by the much smaller body, and the greater abundance 

 of the spirals and the consequent shortness of their curves. 

 The sheath appears to be conspicuously thickened on one mar- 

 gin, and to be thrown into these spiral convolutions because it 

 is too long for the enclosed muscular thread, the latter when 

 extended not being able to entirely straighten it as in most of 

 the other species, the opposite, thinner border at all times 

 clinging to the muscular thread so that it is commonly invisi- 

 ble. The following is the description referred to above : 



