NOTES AND MEMORANDA. 
Rotation of Embryo-Lymnzus.—May I be permitted to call 
the attention of the readers of the ‘ Quart. Journ. of Micros. 
Science’ to a fact which has escaped Mr. E. Ray Lankester’s 
notice in his valuable and interesting inquiry into the “ De- 
velopment of the Pond-Snail” ? 
If Mr. Ray Lankester will do me the favour to turn 
to vol. 11 (1854), page $2,‘ Quarterly Journal of Microscopical 
Science, he will find that I mention the existence of cilia, 
and ascribe the rotatory motion of the embryo to the same. 
I may add that my observations were made with a Ross’s 
half-inch, and therefore I am at a loss to account for the fact 
he mentions, that these cilia ‘have entirely escaped the 
attention of M. Lereboullet.”—Janez Hoae. 
Different Diatoms on the same Stipes.—In the ‘ Quarterly 
Journal of Microscopical Science’ for July, 1873, page 313, 
in the report of the proceedings of the Dublin Microscopical 
Club, Mr. Archer has made some remarks on two distinct 
diatoms presenting the appearance of being on the same 
stipes as bearing on Dr. Bastian’s views. Therein he alludes 
to a paper of mine reprinted in the ‘ Monthly Microscopical 
Journal’ from the ‘Proceedings of the Boston Society of 
Natural History,’ February 9th, 1870. In my paper I stated 
that I found Gomphonema capitatum and constrictum both 
growing upon the same stipes. Mr. F. Kitton, who examined 
my specimens, confirmed my observation, and yet Mr. Archer 
thinks we are both of us mistaken, and that the occurrence 
of these apparently distinct forms upon one stipes was acci- 
dental, and that I have failed to distinguish between actual 
organic genetic relationship and accidental superposition. It 
was on November 6th, 1867, that I first found these two 
species growing upon the same stipes, and showed them to 
several persons, competent observers with the microscope. I 
also sent specimens to Dr. Arnott, as mentioned in my original 
paper. They, unfortunately, did not arrive until after his 
death, and, at my request, they were sent to the Quekett 
Club, where Mr. Kitton saw them and confirmed my dis- 
covery. On the stipes of the Gomphonema was Achnanthes 
minutissima, F.'T. K., after the manner described by Mr. 
Archer. On October 17th, 1869, as well as at other times 
during the preceding summer, I made collections at the same 
