1880.] 



MICEOSCOPICAL JOUENAL. 



nular ; disc well elevated, and 

 higher on one side than on the 

 other. Endoplast or nucleus very 

 long. 



The ciliated oesophagus extends 

 half way to the contractile vesicle. 

 The external surface of the body 

 exhibits very fine, transverse stria- 

 tion. 



During contraction, this striation 

 is not more marked, except in that 

 part below the dilated portion — 

 and in this species it is much less 

 conspicuous than in O. versatile. 



Moreover, during partial or com- 

 plete contraction, the appearance 

 presented is not the same as in O. 

 versatile / the " flask-shape " is 

 never assumed. There are no lon- 

 gitudinal folds like those of 0. 

 versatile, except when the animal is 

 subjected to pressure, and even 

 then they are not always produced. 



I have never seen the animals 

 encysted. I have not seen the 

 acinetiform phase that Stein has 

 observed in O. versatile. 



The animal is not of a vivid green 

 color ; the chlorophyll granules are 

 few, mostly collected in the dilated 

 portion. When fully contracted, 

 the bod}^ is pyrif orm, or nearly oval 

 in shape. The animals are associa- 

 ted in smooth, globular, transparent, 

 homogeneous masses, which are 

 always attached, varying from one- 

 half line to two lines in diameter. 



Length of extended individual 

 about Y^ of an inch (254/^). Ha- 

 bitat, so far as known, only fresh 

 water. Although the locality where 

 I found this rotifer has been fre- 

 ' quently visited during the past 

 spring and summer, and the fauna 

 of the stream studied, these masses 

 were not found until the early part 

 of the past autumn. That they are 

 hardy, is evident from the fact 

 that the water of the jar in which 

 they lived, was frozen, yet they 

 were alive and active after the 



thawing of the ice. This animal 

 appears to be very closely allied to 

 0. versatile., but I believe there are 

 speciiic differences. Its general 

 form is unlike that of O. versatile., 

 the latter is truly fusiform, the 

 greatest diameter, when the animal 

 is extented, is near the middle of 

 the body, and, taking all facts 

 bearing on this point into consi- 

 deration, I regard it as an hitherto 

 undescribed species, and designate 

 it by the name Ojphrydivjin Adm. 



Memorandum ou the Ampli- 

 fiers of Zeiss. 



BY J. J. WOODWARD, SURGEON U. S. 

 ARMY.* 



In a paper recently presoited to 

 the Royal Microscopical Society 

 {Jowrn. of the Royal Mic. Society, 

 Yol. II, 1879, p. 663), I discussed 

 the theory of the use of the ampli- 

 fier in projecting images from the 

 microscope upon a screen, for the 

 purposes of photography, and, in 

 the course of my remarks, alluded 

 incidentally to the new amplifiers 

 advertised by Carl Zeiss, of Jena, 

 last March. In so doing, I re- 

 marked that I was unable to give 

 an opinion as to their merits, be- 

 cause I had not seen them, but ex- 

 pressed the fear that I had myself 

 been, unintentionally, the means of 

 misleading Zeiss, as to the most con- 



* Note. — This memorandum is part of a 

 paper sent, a short time since, to the Royal 

 Microscopical Society. I have, however, been 

 informed by the Secretary that the Council 

 of that Society determined ' 'not to publish that 

 part of it which deals with Tolles and Zeiss, 

 as the latter will want to reply, and so on." 

 I regret this decision the more because there 

 appears to have been no hesitation on the 

 part of the Society, to publish, in the paper 

 referred to in the text, a comparison between 

 certain objectives of Zeiss and Tolles, very 

 much to the favor of the former ; and I am 

 unwilling to think that an American maker 

 must not be praised in England, even for so 

 small a matter as an amplifier. — J. J. W. 



