MEMOIRS OF THE NATIONAL ACADEMY OF SCIENCES. 27 



It is probable that the list of Infusoria will eventually be considerably enlarged when special 

 attention is given to the subject. Our own examinations of water from Wandering Willie's Spring, 

 .Mammoth Cave, taken May3, 1874, and at once examined, revealed three forms of holotrichous 

 Infusoria, which, however, we were unable to identify even geuerically. 



No. 1. Vibrio. Observed iu the water taken from Wandering Willie's Spring. 



No. 2. Colpoda ? . It was a ciliate infusoriau, rounded oval, with well-marked cilia all over the 

 surface. This was the largest form observed. 



No. 3. Nassula ? , or Prorodon ? . Was common in the water, and about half as large as No. 2. 

 It is regularly oval-cylindrical, rounded at each end ; the cilia are short and very minute, scat- 

 tered over the body. There are two round contractile vesicles and a long rod-like nucleus. 



No. 4. This form is longer than any of the others ; long, oval cylindrical, with long sparse 

 cilia, and a distinct mouth-opening; it is more like Paramecium than any of the other forms. 



VERMES. 

 Vortex ? cavicolens Pack. 



Vortex cavicolens Pack., Auier. Naturalist, xvii, 89, January, 1883. 



|^-.oe/. 

 Fig. 5. Plauariou Worm, Carter cares: o. dorsal; 6, ventral, 6 x maguifito : c natuial size, ventral; p, prr lioscia. (Gissler del.) 



This Rhabdoccelous worm was found iu a brook in X Cave, one of the Carter caves, Kentucky. 

 It belougs near Vortex, and it may provisionally be called Vortex cavicolens. The body is flat, 

 elongated, narrow, lanceolate-oval, contracting in width much more than is usual in Vortex. The 

 pharynx is situated much farther back from the anterior end of the body than usual in Vortex, 

 being placed a little in. front of the middle of the body ; it is moderately long, being oval in out- 

 line. The body behind suddeuly contracts just before the somewhat pointed end. The genital 

 outlet is about one-half as wide as the pharynx and orbicular iu outline/ Though described from 

 two alcoholic specimens, I can discover no eyes, nor do I remember seeing any when it was living; 

 it was when alive white, and apparently eyeless. Length, 4 mm ; breadth, 1.5 mm . Found by us 

 in X Cave, one of the Carter caves, eastern Kentucky. 



This worm may not prove to be a genuine Vortex, the species of which are broad and blunt iu 

 frout, with the pharynx much nearer the front eud than in the present species, which is therefore 

 only provisionally placed in the genus Vortex. In Vortex ccecus OErsted, the eyes, as the specific 

 name implies, are wanting, but most of the species have eyes. As our species occurred in a 

 brook in a dark cave, it would naturally, as in the case of the Mammoth Cave eyeless white Plana- 

 rian, be eyeless, and as a consequence of losing its eyes become white. Schultze, in his Naturge- 

 scbichte der Turbellarien, states that Vortex mridis in winter was generally without chlorophyl 

 bodies and wholly white, but that in April the white individuals are rare. He then adds : " Kept 

 for a considerable time in darkness, the green animals become, through bleaching and the disap- 

 pearance of the chlorophyl, almost colorless." 



Upon sending the above description of the single alcoholic specimen to Professor von Graff, 

 of Aschaffenburg, he very kindly replied as follows : 



As to the systematic position of the doubtful Turbellarian, I can, unfortunately, not form a precise opinion. 

 According to your short description it may be a Vorticide orMesostomide, and it would seem to correspond to the last 

 family in the llatness of the bouy and the size, since there are few Vorticidse so flat and large. 



