whose larve are external feeders. 339 
too deep for this she will lay them on a spray of the moss, 
always in little groups, rarely as few as two or three, 
usually six to ten and even more. I have counted as 
many as twenty-five. She will often remain and die 
beside her last batch of eggs. I prepared various jars 
with mosses of different sorts, and especially several with 
growing Mniwm, which I thought might be the proper 
food, but in this I proved to be mistaken. 
About the middle of August, 1892, I found several larve 
of calthella about 1°5 mm. in length in ajar in which some 
moss was growing, but I could see none in my specially 
prepared pots of Mniwm, nor indeed in any of the other 
jars; these larva, though so much larger than the newly- 
hatched ones, were precisely the same in all respects, so 
far as I could see without disturbing them. They were 
kept very wet, the moss dripping and the sand below 
under water, in consequence of my directions to keep them 
moist during a temporary absence being misunderstood. 
The result, however, was decidedly satisfactory, and at 
the end of September the moss was still growing, and 
there were two larve usuaily to be seen of a length of 
about 2mm. On October 21 I found there were three 
larvee in this jar, the two largest measuring with the head 
retracted 3°5 mm. in length, and therefore probably full 
grown. 
I also found several about 1:3 mm. in length in another 
jar in which moss was growing, but which had been kept 
much too dry. In one of the Mniwm jars there was also 
one about 1:5 mm. long, seen for the first time close by 
where a bit of moss (not Mniwm) was growing. I was 
on this date successful in making two other observations. 
One was in seeing one of the larvae in my best jar actually 
eating the delicate stem of growing moss, of which a con- 
siderable piece of one side had disappeared. The other 
was due to one of the larvee having got on to the glass, 
when not only was it easy to see that it resembled the 
newly-hatched larvee as to processes, abdominal legs, etc., 
but that it also possessed the trefoil sucker. These 
larvee seemed to be constantly on the move, at times 
not to be seen, and when seen always in a fresh place ; 
they walk slowly but steadily, using the abdominal 
appendages as legs, and often raising the fore part of the 
body and stretching about as if in search of something. 
They are not cannibals, as one walked straight along 
