D. Keilin 
217 
Some of the larvae were then divided into three pieces, and transferred 
from the formalin medium in which they were mounted into distilled water, 
in which they were allowed to remain for about an hour. They were then 
stained in a strong solution of haemalum, differentiated in alcohol (30 per cent.) 
to which a little hydrochloric acid had been added, and washed for a few 
minutes in tap-water. The pieces were then passed slowly through the graded 
alcohols, cleared in clove oil followed by xylol, and then into very liquid Canada 
balsam. Some of the pieces were mounted whole, but others were teased up 
in a drop of balsam, using a high magnification of the binocular microscope 
and very fine needles, with the object of liberating the stained parasites from 
the body of the host. When the parasites were well scattered in the balsam, 
a cover-glass, which had been momentarily immersed in xylol, was dropped on. 
Other portions of the larvae were embedded in paraffin and sections cut, 
but the latter proved to be less instructive than the teased preparations. 
Of the eight larvae examined, two proved to be free from parasites; they 
had been included in the lot on account of their mutilated condition, both 
having been found dead, with three gills missing, a condition which it was 
thought by Lamborn might be attributed to a parasitic infection. Five of 
the larvae showed the presence of the Ciliate parasite, but the sixth was the 
host of a fungal parasite with which I am dealing in another paper. 
II. Lambornella stegomyiae , n.gen., n.sp. 
The ciliate about to be described is a new form, and I have named it in 
honour of its discoverer—Dr W. A. Lamborn 1 . 
The parasite is found distributed throughout the body-cavity of the host, 
from the head to the anal segment, and even penetrates to the respiratory 
siphon and the gills. Fig. 1 shows the appearance of the posterior extremity 
of a parasitised larva as seen by transmitted light. Sections of the same larva 
show no obvious damage to the internal organs, with the exception of the 
fat-body which, in places, has disappeared completely, while the parts which 
remain are reduced to a few cells devoid of fat-droplets. 
The condition of each of the five parasitised larvae was as follows: 
Larva No. 1. One of the four gills missing; body filled with parasites, as 
represented in Fig. 1. 
Larva No. 2. Parasites scattered throughout the body-cavity; all four 
gills present, one of which is tightly packed with parasites, another moderately 
invaded, and the other two with very few ciliates; parasites very numerous 
in the respiratory siphon, surrounding the tracheal trunks. 
Larva No. 3. Ciliates numerous in the posterior segments, scattered in 
the head and the remaining segments; two of the gills are missing, one of the 
remaining gills contains numerous parasites in its proximal portion only, the 
1 The name Lambornia is preoccupied for an Insect (Lepidoptera, Geoinetridae; Prout, 
Genera Insectorum, 1912, p. 235). 
