80 
NOTES AND MEMORANDA. 
part. When the diatom moved it pushed before it a cordon of particles 
of indigo, which kept always at the same distance from the anterior 
portion of the frustule, and which were repelled during the movement 
of the diatom. A very slight application of red aniline (Fuchsine) 
demonstrated conclusively the existence of the gelatinous envelope 
ordinarily invisible ; for it colours it distinctly even before the tint 
has made its appearance in the field of the microscope. Aniline always 
instantly stops the motion of diatoms with which it comes in contact.” 
Abnormal Appearances of Hydra viridis. — Mr. Sydney J. Hickson, 
while examining specimens of this polyp in Professor Lankester’s 
class. University College, noticed one which exhibited twelve or 
fourteen sperm sacs, although it was budding at the same time. The 
young budded hydra had one tentacle, with a short oval outgrowth at 
the tip, giving it a forked appearance, and below the normal row of 
tentacles was a second row. The parent polyp exhibited a constriction 
a little way below the tentacular rov/, and from the constricted part 
sprang three tentacles, forming an incomplete second row. These 
three tentacles were more sluggish in motion than the others. In the 
course of a week the bifid tentacle disappeared, one half having pro- 
bably dropt off ; the sperm sacs increased in size and some burst, and 
a definite constriction appeared towards the basal end, as if fission 
were commencing. An unfortunate accident prevented further ob- 
servations. Mr. Hickson observes that Johnston cites the following 
passage from ‘ Baker on the Microscope ’ : — “ Instead of buds of little 
protuberances, the body sometimes pushes forth single tentacula 
scattered irregularly over it, and these can be metamorphosed into 
perfect polypes, the base swelling out to become the body, which 
again shoots out additional tentacles to the requisite number.” 
Bhizopods in an Apple-tree . — Professor Leidy mentions that while 
waiting at Swarthmore for the train to return home, his attention 
w'as attracted to a large apple-tree which shortly before had been 
prostrated by a storm. In the fork of the trunk there was a bunch 
of moss which he collected and took home. On washing the moss 
and examining the water, he was not a little surprised to find in it 
many rhizopods. Of these, one was Difflugia cassis, and was abundant. 
Another was Difflugia glohularis, few in number. The others were 
Trinema acinus, Euglypha alveolaia, and Euglyplia hrunnea. The 
position of these animals, in the moss on the tree, was about eight 
feet from the ground.* 
On an Ostracode Crustacean of a neio Genus (Acanthopus), met ivith 
in the deep Waters of the Lake of Geneva. By M. H. Vernet. — This 
entomostracan cannot be referred to any type hitherto observed in 
fresh water ; it belongs to the marine family Cytheridas. Like the 
representatives of that family, it possesses only a single pair of max- 
illa3, and, on the other hand, three pairs of feet armed with strong 
hooks at their basal articulation (the other fresh-water Ostracodes 
having two pairs of maxillaa and two pairs of legs). The rudimen- 
* ‘ Proceedings of the Academy of Natural Sciences of Pliiladeli)liia,’ Doc. 18, 
1877. 
