Agarella gracihs. 213 
XX VII.—Agarella gracilis, a new genus and species of Myxosporidian, 
parasitic in Lepidosiren paradoxa. By J. S. Dunkerly, B.Sc., 
Glasgow University. 
(With Plate.) 
(Read 22nd February 1915. MS. received 22nd February 1915.) 
In the course of his work [1] on the spermatogenesis of Lepidosiren paradoxa, 
the South American lung-fish, Dr W. E. Agar discovered certain bodies in 
the testis which he took to be parasitic Protozoa. He was good enough to 
give me the opportunity of examining these bodies, and to this end he not 
only allowed me the use of his mounted smears and sections of testes but 
supplied me freely with further material collected and preserved by him, and 
I am glad to take this opportunity of thanking him for his kindness in this 
matter. 
I had completed a description of this parasite, and the MS. and drawings 
were sent to Germany on the 25th July last for publication in Archw fiir 
Protistenkunde, but as war was declared between Engiand and Germany on 
Ath August, there is little chance of my paper being available in that journal 
for some time to come. The following account, therefore, is a slightly 
abbreviated account of the work, together with drawings of the more 
important stages. 
The parasite is a Myxosporidian belonging to the family Chloromyxide, 
and was studied by means of sections and smears of testis. The smears were 
especially useful, and had been fixed with corrosive acetic mixture and 
stained with Delafield’s hematoxylin by Dr Agar. Some of these I 
unmounted and restained with iron-alum hematoxylin, and the different 
aspects presented by the two methods of staining have a certain amount of 
interest. 
As regards the name and systematic position of this form, the spores 
(Pl. VIII. Fig. 12) differ from those of the genus Chloromyxum in being elongate, 
slightly flattened in the sutural plane, and in possessing a long bifid tail 
composed of an elongation of each spore valve posteriorly. The form of the 
spore, therefore, exactly resembles that of Henneguya, from which it differs, 
however, in possessing four polar capsules—the characteristic mark of 
members of the family Chloromyxide. Thélohan [13] described a species of 
Chloromyxum (C. caudatum) with an “appendice posterieure . . . comme chez 
les Henneguya parfois bifurgé,’ but its proportions and form are different 
from those of a typical Henneguya, and from those of the form described in 
this present paper. It resembles more a Chloromyxum with a well-developed 
tuft of hairlike processes posteriorly, such as Chloromyxwm leydigi often shows. 
