Stokes.l '^'^^ [Nov. 2, 



Results. 



•WO3 HoO AT. MASS W. 



0.983034—0.22834—184.683 

 0.998424—0.23189—184.709 

 ] .008074— 0.23409— 184.749 

 0.911974—0.21184—184.678 

 0.997974—0.23179—184.704 

 1.007024-0.23389—184.706 



Mean 184.704 



Maximum 184.749 



Minimum 184.678 



Diff 071 



The mean IS^.704, falls below that given by Pennington and Smith. 

 The discrepancy may possibly be due to the method, or the personal factor 

 entering into the vpork may account for it. However, the result we 

 believe clearly proves that the atomic mass of tungsten is certainly greater 

 than vi'hat is generally assumed as correct, and in all likelihood the 

 molybdenum contained in the tungsten has caused the low values found 

 bj previous experimenters.* 



Chemical L.\boratort, University op Pennsylvania, 

 November, 1894. 



Notices of Presumably Undescribed Infusoria. 



By Dr. Alfred C. Stokes. 



{Read before the American Philosophical Society, November 2, IS94.) 



Salpingceca globosa, sp. nov. (Fig. 1). — Lorica pedicellate, carafe- 

 shaped, the body subspherical, tapering at the posterior extremity to 

 the pedicle ; neck conspicuous, about one third as long as the body of 

 the lorica, the margin flaring ; pedicle often oblique, somewhat flexuous, 

 and about as long as the entire lorica. Solitary. Length, -^^^-^ inch. 

 H«&.— Fresh water, near Trenton, N. J.; attached to filamentous algae. 



Salpingmca collaris, sp. nov. (Fig. 2). — Lorica vasiform, less than 

 four times as long as broad, but divisible by its characteristic contour 



* A review of all the methods heretofore used in determining the atomic ma«s of tung- 

 sien has been begun by oue of my assistants. Care is being taken to completely elimi- 

 nate certain sources of error which have not been absolutely excluded in earlier work. 

 — E. F. 8. 



