47 



transparent, the markings would of course show through ; but 

 the capability of the i lens was what, in this case, it was desired to 

 demonstrate, and it would be equally competent to take opaque 

 objects. 



Mr. E. M. Nelson thought the photograph shown was a very 

 remarkable one, considering the enormous area covered and the 

 flatness of the field. He was much astonished to see that this 

 was not accompanied by a falling off in the sharpness of the 

 detail. As a* rule large covering power is obtained by sacrificing 

 sharpness. In the example before them this evening he thought 

 the image as sharp, if not sharper, than any taken with the 

 old form of lens, which had far less covering power. 



A vote of thanks to Dr. Measures for his exhibits was pro- 

 posed by the President, and carried unanimously. 



Mr. C. Kousselet read a paper '' On some Little-Known 

 Species of Pterodina,^^ illustrated by drawings. 



A vote of thanks for the paper was unanimously passed. 



Mr. T. B. Rosseter read a paper " On the Generative Organs 

 of Drepanidotcenia venusta Eosseter," in which he described his 

 further researches into the life history of certain taenoid parasites 

 found in ducks, and his discovery of the scolex forms. The 

 paper was illustrated by drawings on the blackboard, and a 

 hearty vote of thanks was given to Mr. Rosseter for his com- 

 munication. 



Mr. Karop said they were always exceedingly pleased to hear 

 of the work Mr. Rosseter was doing, but unfortunately the 

 subject was one which they were unable to discuss, because 

 hardly any one seemed to know anything about it. Mr. Rosseter 

 seemed to be the only one who was studying the tape-worms 

 at the present time. 



Mr. Rosseter said he quite felt his position in this respect, 

 and should be only too glad if some one would help him in these 

 investigations ; and he asked members generally if they found 

 anything of the kind in the course of their pond hunting to 

 forward it to him. 



Notices of meetings, etc., for the ensuing month were then 

 made, and members were reminded that the next Ordinary 

 Meeting would be their Annual Meeting. 



